Brazilian zoologists have identified which specific insects and spiders are most frequently hunted by domestic cats in urban areas, using not traditional field observations, but by analyzing content from social media. The researchers reviewed over 17,000 videos and photos on platforms like TikTok and iStock, selecting 550 records where cats were seen hunting arthropods. The most common prey were grasshoppers, crickets, cicadas, and cockroaches.

Cats as Invasive Predators

Domestic cats are considered dangerous invasive predators, capable of hunting birds, reptiles, and mammals of suitable size. However, they also actively prey on invertebrates—beetles, spiders, and other arthropods. For example, in Australia alone, cats destroy more than a billion invertebrates each year.

Challenges in Studying Invertebrate Hunting

Studying the invertebrate diet of cats is difficult because traditional methods like fecal analysis are not very effective: the chitinous exoskeletons and wing covers of insects are destroyed in the digestive system and are poorly preserved. Therefore, the authors of a new study published in the journal Insect Conservation and Diversity decided to investigate what cats hunt by analyzing data from social networks.

Using the iEcology Method

The study employed the iEcology method, which involves studying wildlife through incidental evidence collected online. Proponents of this approach believe that the sheer volume of such data allows researchers to track the spread of invasive species, determine seasonal changes from photos of blooming trees, and analyze the behavior and interactions between species.

The researchers analyzed 17,000 materials from TikTok and iStock, selecting 550 photos and videos where cats attacked arthropods and the prey species could be clearly identified. Searches were conducted using phrases like “cat insect” and “cat hunting insects” in English, Portuguese, and Spanish. To avoid the influence of TikTok algorithms, a separate account was created.

Analysis Results

The analysis showed that cats hunt representatives of 14 orders of arthropods—essentially anything that moves. The most frequent victims were:

• Orthoptera (grasshoppers, crickets) — 20.7%
• Hemiptera (mainly cicadas) — 14.5%
• Cockroaches — 14.4%
• Butterflies and moths — 11.5%
• Beetles — 9.1%
• Wasps, bees, and ants — 8.5%
• Dragonflies — 7.1%
• Spiders — only 4% of cases

Comparison with Traditional Studies

The results were then compared with traditional studies of cat diets based on fecal analysis. In a 2023 review, beetles ranked first, followed by orthopterans, then butterflies and moths, with arachnids in fourth place. Cockroaches did not make up a significant portion of the prey in traditional studies. Meanwhile, centipedes (such as scolopendras and millipedes) appeared in classic reviews but were absent from the social media analysis.

Reasons for the Differences

The predominance of grasshoppers is explained by their large size, widespread presence, and distinctive chirping, which attracts predators. The differences between the results are due to the fact that traditional studies often focus on cats living in the wild, where cockroaches are scarce but centipedes are more common.

Conclusions

The scientists concluded that data collected from social networks cannot fully replace traditional analysis methods, but they can help fill gaps and broaden our understanding of the diet of domestic cats.