The recruitment of participants was opportunistic. Surveys were conducted at three separate locations on the University of Wisconsin – Madison campus in November of 2022. Campus locations were near cafeterias, dorms, and/or parking lots. In November of 2023, participants were recruited at the East Bluff Woods trailhead at Devil’s Lake State Park, Baraboo, WI. For both years, we aimed to set up tents in areas with high foot traffic, near communal gathering spots, and had open, flat space for the tents and mannequins to remain level. Team members would inquire of passersby if they were interested in the survey, explaining its importance in tick bite prevention research as well as the prizes they would be entitled to with their enrollment. Participants were required to be at least 18 years of age to enroll in the study. We used incentives in the form of participation gifts (e.g. Playing cards, water bottles, tumblers, small plushies, etc.) valued between 1-6 US dollars. In 2022 we had an additional incentive by offering entry into a raffle where the winning entrant selected a prize from a pre-approved list of items valued between 120-200 US dollars. No personal identifiers were linked to the survey, and receiving gifts or prizes was independent of answers or results. valued between 1-6 US dollars. In 2022 we had an additional incentive by offering entry into a raffle where the winning entrant selected a prize from a pre-approved list of items valued between 120-200 US dollars. No personal identifiers were linked to the survey, and receiving gifts or prizes was independent of answers or results.

In both years of the study, participants received a packet including an HRP-502(a) consent sheet, a screening sheet, a nine-part questionnaire, and images of mannequin silhouettes (Supplementary File S1). The questionnaire asked for the following demographic information: gender, age, occupation, state/region of residence, and country of origin. For analysis, participants were categorized as originating from a “high incidence” Lyme disease state if their given state of origin was classified as such by the CDC (Kugeler et al. 2024). The CDC defines a region as high incidence if there are 10 or more confirmed cases per 100,000 individuals for three years. Participants from all other US states and territories, and participants originating from abroad were categorized together as originating from a low incidence region. Additionally, there were five questions about knowledge, attitudes, and behavior (KAB) related to ticks, TBDs, and outdoor activities. Participants reported their frequency of outdoor activities during May through November and then rated their agreement on a 5-point Likert scale with 1 equating to “strongly disagree” and 5 to “strongly agree” to the following four statements:

For descriptive statistics, we grouped Likert scale responses of 1 and 2 as “disagree” and 4 and 5 as “agree”.

After completing the questionnaire, participants were informed that they would have up to 5 minutes to perform a tick check on a mannequin. Researchers told participants to do the check the way they would normally conduct one on a friend or relative at the end of a hike. They were instructed to place a 6.4-millimeter diameter sticker (Avery Products Corporation, Brea, California) on a paper sheet with the mannequin's silhouette, corresponding to where they detected a tick. They were not told how many ticks were on the mannequin.

Tick checks were performed in a partially enclosed tent to prevent those waiting from observing participants in the tent (Fig. 1). Only one participant was allowed in the tent at a time, and no member of the research team was present while a tick check occurred. The research team did not provide information or documentation to participants pre- or post-survey about life stages, species, or number of ticks that were on the mannequins. Research team members reset the poses, clothes, and hair of each mannequin and checked that ticks remained in place after each participant to standardize the initial presentation. Ticks used in this study were collected in 2019 in a city park in Eau Claire, Wisconsin, and preserved in 70% ethanol. Ticks were identified to species and life stages using standard keys (Clifford et al. 1961, Keirans and Litwak 1989, Keirans et al. 1996).

Mannequins were 175 centimeters tall, female presenting, and constructed out of polypropylene (model numbers MK-175 and MK-F61; Factory Direct Wholesales LLC, Duluth, Georgia). In 2022, the mannequins were dressed in an untucked plain, white cotton T-shirt (Fruit of the Loom, Inc. Bowling Green, Kentucky); ankle-length, dark blue denim jeans (Prana Company, Carlsbad, California); white running shoes (Athletic Works, Walmart Inc. Bentonville, Arkansas); and a shoulder-length brown hair wig that fell partially forward. In 2022, a total of 16 unfed (flat) I. scapularis – 2 larvae, 10 nymphs and 4 adults (2 females, 2 males) – were attached to clothing on each mannequin (at locations indicated by life stage in Fig. 2). To attach ticks, we used the end of a 2 millimeter diameter wooden dowel rod (Walmart Inc. Bentonville, Arkansas) to place a small dot of glue (Elmer’s Products, Inc. Westerville, Ohio) to the clothes. Ticks were then placed dorsal side up on top of the glue dot with forceps. Ticks were equally distributed on light and dark clothing. All larvae, six nymphs, one adult male and one adult female were below the waistline of the mannequin. Four ticks, one adult male and three nymphs, were hidden from direct view by clothing or hair. Tick locations were identical on both mannequins. The location characteristics were above or below the waistline, clothing color, and covered or uncovered.

In 2023, mannequins were dressed either in an all-black or all-white outfit consisting of running shoes (Skechers USA Inc., Manhattan Beach, California), ankle socks (Hanes, Winston-Salem, North Carolina), a short sleeve shirt (Athletic Works, Walmart Inc., Bentonville, Arkansas), long athletic style pants (All In Motion, Target Corporation, Minneapolis, Minnesota), and a shoulder-length wig with the hair down. The clothing was identical apart from fabric color. Twenty ticks, 10 nymphs and 10 adults (5 females and 5 males), were in the same locations on both mannequins (Fig. 3). Six nymphs, three adult males and two adult females were attached below the waistline. Three nymphs, one adult male, and one adult female were obscured by the shirt or hair.

Each tick was assigned an identifier (Fig. 2, 3, Table 1, 2) which was linked to location characteristics and life stage. A tick was scored as detected if a sticker was in the expected location of that tick. Locations on the sheets were graded independently by two members of the research team to prevent biases in the scoring. An intraclass correlation coefficient was calculated (Gamer et al. 2019), and we checked the overall agreement and the agreement on the detection of individual ticks. The overall scoring had a high level of agreement (2022: 0.93 ± 0.01, p <0.001; 2023: 0.88 ± 0.01, p <0.001), and the kappa values per tick showed substantial to almost perfect agreement depending on the tick (2022: 0.89 ± 0.02; 2023: 0.86 ± 0.02; Supplementary File 2). We interpreted the kappa values following Landis and Koch (1977). For the rest of the analysis, the scoring values by one research team member were used.

The first generalized linear model was used to assess the relationship between the response variable (i.e. the number of ticks successfully detected), and the explanatory variables, including demographic characteristics, knowledge of ticks, origin from high- or low-incidence regions, and frequency of outdoor activities. When there were few responses to a particular question at a Likert scale level, participants were merged with levels of like agreement to avoid skewing the model. Therefore, we combined “Outdoors” 1 and 2, “Knowledge” 4 and 5, “Concern” 1 and 2, and "Confidence” 4 and 5. In the second generalized linear mixed-effect model, we investigated the location characteristics and life stage that predicted the likelihood that a tick was found, and we included participant (survey ID) as a random factor.

All models were checked for variance inflation factors (VIF; Belsley et al. 2005) and the levels of significance were established by log-likelihood ratio tests (Lewis et al. 2011). In 2023, the variables related to knowledge of ticks and confidence in tick checks showed elevated VIF values, raising concerns about multicollinearity. To assess the impact of this collinearity, we ran models with and without these variables and found no significant differences indicating that collinearity did not substantially affect the results. All analyses were conducted in R (4.4.1; R Core Team, 2024) using the packages broom (1.0.6 Robinson et al. 2024), broom.mixed (0.2.9; Bolker and Robinson, 2024), car (3.1-3; Fox et al. 2019), lme4 (1.1.35; Bates et al. 2015), lmtest (0.9.40; Zeileis and Hothorn 2002) and lsmeans (2.30; Lenth 2016).

In total, 207 people participated in our study, 96 in 2022 on the UW-Campus and 111 in 2023 at a state park (Table 3). Some participants (n = 6) did not answer all the questions on the survey. Most participants (92%, 190/207) were between the ages of 18 to 54. There was an almost even number of people, 100 and 101 respectively, who identified as male and female. Four participants identified as non-binary, and two preferred to not say. Eighteen nationalities were represented in the study, with the majority (184/206) originating from the US. Of the US participants, 65% (120/184) were from high incidence states. The high incidence states listed by participants in our survey were Connecticut, Maryland, Minnesota, New Jersey, New York, Pennsylvania, Washington DC, and Wisconsin.

Seventy-six percent (158/207) of participants said they spent time outdoors at least weekly during peak I. scapularis months. A little over half (114/201) of participants agreed with the statement that they were knowledgeable about ticks and TBD compared to 30% (60/201) who disagreed. Slightly under half (97/201) felt confident in their ability to find ticks and 23% (47/201) were not confident. Almost two-thirds of participants (135/201) indicated that they were concerned about ticks and TBD, however, of these 135 participants only 50% (68/135) agreed that they regularly performed tick checks. This was only slightly higher than the overall percentage of 42% (85/201) of participants who agreed that they performed tick checks regularly. Similarly, 43% (65/152) of participants that reported being outdoors at least weekly agreed that they performed tick checks regularly. Only 12% (7/60) of participants who disagreed with the statement about being knowledgeable about ticks and TBD agreed that they regularly check themselves for ticks, while those who considered themselves knowledgeable checked for ticks 60% (68/114) of the time.

There were some differences in responses between the two study years that were related to the different locations. Participants in 2022 in the campus study were younger with a median age of 19 compared to 34 in 2023. A larger percentage of participants originated from a high incidence state in 2022 (63%, 60/96) than in 2023 (39%, 43/110), where park visitors reported Illinois as the most frequent home state. Participants in 2023 agreed with the statements about knowledge (70%, 74/105), confidence (59%, 62/105), and frequency (51%, 54/105) of tick checks more often than their 2022 counterparts (41% 40/96; 36%, 35/96; 32%, 31/96).

Gender (2022: χ² = 0.13 , df = 3, p = 0.988; 2023: χ² = 2.30, df = 3, p = 0.513), region of origin (2022: χ² = 1.12, df = 1, p = 0.290; 2023: χ² = 1.22, df = 1, p = 0.269), time outdoors (2022: χ² = 3.74, df = 3, p = 0.290; 2023: χ² = 3.41, df = 3, p = 0.332 ), knowledge (2022: χ² = 4.49, df = 3, p = 0.214; 2023: χ² = 3.76, df = 3, p = 0.288) , concerns (2022: χ² = 1.30, df = 3, p = 0.729; 2023: χ² = 0.32, df = 3, p = 0.955), confidence (2022: χ² = 2.42, df = 3, p = 0.489; 2023: χ² = 1.38 , df = 3, p = 0.709), or self-perceived experience at performing tick checks (2022: χ² = 2.88, df = 4, p = 0.579; 2023: χ² = 0.92, df = 4, p = 0.922) did not significantly predict the number of ticks a participant found. This remained true when results were stratified by tick life stage.

No participant detected all ticks on a mannequin. In 2022, the median number of ticks found by participants was seven (range = 0-13 out of 16). The median number of detections was zero larva (range = 0-2 out of 2), four nymphs (range = 0-8 out of 10), one adult male (range = 0-2 out of 2), and two adult females (range = 0-2 out of 2). Tick 14 (adult male) and Tick 2 (larva) were respectively the most and least commonly found ticks with 78% (75/96) and 4% (4/96) of the participants detecting them in 2022 (Table 1, Fig. 2). In 2023, the median number of ticks detected on the white and black clothed mannequins was 14 (range 4-14) and 10 (range 0-16) out of 20, respectively. The median number of nymphs (n=10), adult males (n=5), and adult females (n=5) on the white-clothed mannequin was 7, 4, and 4 (range 1-10, 1-5, 1-5) while the black-clothed mannequins had medians of 4, 3, and 3 (range 0-8, 0-5, 0-5). Tick T (nymph) was the least detected tick for both the white and black mannequins with 31% (17/55) and 11% (6/56) of participants detecting the tick, respectively (Table 2, Fig. 3). Tick D (adult male) (97%, 53/55) was found the most on the white-clothed mannequin and Tick O (adult female) (79%, 44/56) was found the most on the black-clothed mannequin (Table 2, Fig 3).

The life stage of the tick had a significant effect on the likelihood of being found by participants. Specifically, the likelihood was the lowest for larvae (2022: estimate = −1.76; p-value = <0.001) and the highest for adult females (2022: estimate = 1.39; p-value = <0.001, 2023: estimate = 1.01; p-value = <0.001). Participants were 4 and 3 times more likely to detect an adult female than a nymph in 2022 and 2023, respectively. Nymphs were 6 times more likely to be detected than larvae.

Ticks above the waistline were more likely to be detected compared to ticks below in both 2022 (13-fold, estimate = 2.85, df =1, p-value < 0.001) and 2023 (3-fold, estimate = 1.32, df = 1, p-value < 0.001). In 2022, two larvae were included, and both were glued to the shoes which may have biased this comparison since they are very small (no larvae were used in 2023). However, even when only nymphs were included in the 2022 model, participants were still much more likely to find those above the waistline than below (23-fold, estimate 3.12, df =1, p-value < 0.001). In 2022, mannequins were dressed in dark jeans and light-colored shirts. This additional variable may explain why the likelihood of detection of any tick above the waist was so much higher in 2022 (13-fold) when compared to 2023 (3-fold) when mannequins wore either all dark or all light clothing.

Ticks that were not covered by either clothing or hair were more likely to be found (2022: 2-fold, estimate = 0.57, df =1, p-value < 0.001; 2023: 2-fold, estimate = 0.71, df =1, p-value < 0.001) than those that were covered.

The color of the clothing was not significant in 2022 (estimate = −0.3, df = 1, p = 0.143). However, this year, the dark jeans were restricted to below the waistline, potentially confounding the model. In 2023, there was a significant increase in the likelihood of a tick being detected when on light-colored clothing (3-fold, estimate = 1.15, df = 1, p-value < 0.001). In 2023, 19 of the 20 ticks were detected more often on white-colored clothes than black-colored clothes (Table 2). Only Tick L was detected more often on the black-clothed mannequin.