When Do Venomous Snakes Attack? Researchers Tested Them 40,000 Times and Got a Surprise

What makes a venomous snake attack a person? An unusual Brazilian study tried to answer that question through nearly 40,000 tests on 116 Bothrops jararaca snakes, a species common in Brazil.

The researchers did not simply observe the snakes from a distance. They measured the animals’ responses under different conditions, testing variables including temperature, the time of day and the part of the body where pressure was applied. The experiments examined how the snakes reacted when pressure was placed on different points and when they were more likely to attack.

The results pointed to several factors that could raise the risk of an attack: higher temperatures, a smaller snake and pressure on certain areas of its body. Scientists said the aim was to understand the animals’ attack behavior better and use the findings to help prevent snakebites.

The study also drew controversy for reasons beyond its striking method. Scientific Reports withdrew it in 2025 because of issues connected to ethical approval for experiments involving animals. Despite that, the research returned to attention in September 2026 after it became one of the studies recognized by the Ig Nobel Prizes.

The Ig Nobels honor research that may initially seem funny, pointless or bizarre but rests on a genuine scientific question. The award does not mean that the experiment’s method should serve as a model for science. Its central idea is to bring studies to public attention that first make people laugh and then make them think.