The severe impact of domestic cats on vertebrate biodiversity is unequivocal. However, cats are generalist predators that also hunt various invertebrate taxa, yet we are still far from understanding the impacts of these predators on arthropod populations. Here, we analyzed records from social media to explore which arthropods are most preyed upon by domestic cats in urban environments.

Using the search algorithms of two online platforms, iStock and TikTok, we analyzed >17,000 photos and videos, which yielded 550 records of predation events by domestic cats. We examined these images to identify the orders of arthropods most frequently preyed upon by cats. We compared our findings with data from a recent global synthesis of academic papers quantifying the diet of domestic cats.

In total, we recorded 14 distinct arthropod orders killed by domestic cats. Orthoptera was the most frequently preyed upon order, accounting for 20.7% of the records. Hemiptera (14.5%) and Blattodea (14.4%) were also commonly observed. Our data show that domestic cats hunt a surprisingly diverse range of arthropods in urban settings.

Overall, the data collected from social media showed similarities but also some differences compared to the general patterns found in the scientific literature on the diet of domestic cats. This finding emphasizes that these different data streams are not redundant; therefore, combining them can be an effective way to thoroughly document ecological interactions in urban environments.

Social media serves as a powerful and rapidly growing source of biodiversity data for ecologists and conservation biologists. Our study presents new records of arthropod predation by cats and highlights the diversity of invertebrate prey killed by domestic cats in urban settings. Together, these findings offer new insights into the neglected impacts of cats on arthropod populations.

Data collection

We collected data on TikTok and iStock between March and April 2024. To gather data from both platforms, we used search terms related to cat predation on arthropods (see details below) and only selected records—whether photos or videos—that depicted: (i) cats consuming arthropods, (ii) cats hunting or chasing arthropods or (iii) cats interacting with arthropods (e.g., cats attempting to capture, stalking, or preparing to attack an arthropod). To allow for precise identification of the arthropod at the taxonomic level of order in each photo, we only considered photos and videos where the prey killed or targeted by the cat was clearly visible. Photos and videos with barely visible prey or those that did not show the prey were discarded. We also removed photos and videos that appeared manipulated, showed significant human interference (e.g., a human offering prey to a cat), or were taken in potentially non-urban environments. Since iStock and TikTok have different search mechanisms, we employed specific methods for each platform, as described below:

iStock

In a preliminary analysis of the platform's search tools, we identified that using the same search terms in Portuguese, English, and Spanish resulted in very similar results. Therefore, we conducted searches in English. First, we used the search terms “cat insects” and then “cat hunting insects”. The use of the plural or singular search terms yielded similar results. We used only two combinations of search terms as the search results were numerous. We analyzed the first 6,000 photos and videos for each combination of the search terms, totalizing 12,000 photos.

TikTok

As the search language drastically changed the results obtained, we performed independent searches in English, Portuguese, and Spanish. To avoid content recommendation algorithms present on the platform, we created a new account specifically to carry out the search. Unlike iStock, searches on TikTok return more specific results, so we conducted the search in two stages, one more general and another more specific. For the general search, we analyzed the first 200 videos resulting from each of the following search terms: “cat insects” and “cat hunting insects” in English, Portuguese, and Spanish (i.e., we analyzed 600 videos for each search term). The use of the plural or singular search terms yielded similar results. As the platform has a more specific search algorithm, we conducted additional searches combining “cat” with the popular names of the arthropod orders most prevalent in general search, i.e., ant, bee, beetle, butterfly, cicada, cockroach, cricket, dragonfly, fly, grasshopper, mantis, mosquito, moth and spider. These more specific searches were also carried out in English, Portuguese, and Spanish, and the first 100 videos corresponding to the search were analyzed. Videos that appeared in both the general and specific search were considered only once. Only on TikTok, we analyzed 5,150 videos.