You are all aware that humans have feelings of revenge, but you might be surprised to learn that birds can exhibit a similar tendency. Experts claim that crows are among the birds who hold grudges and seek revenge. A study has found that if crows hold a grudge against a human, they can remember it for as long as 17 years and might even seek revenge.

Research by Professor John Marzluff, an environmental scientist at the University of Washington discovered this unusual happening. In 2006 he experimented to find whether the crows seek revenge or not. During the experiment, he wore a demon mask trapped seven crows in a net and marked their wings for identification. After this, he released them unharmed but even after their release, the crows continued to follow him. Each time, whenever he wore the demon mask, they followed and attacked him.

Even more shocking, other crows joined in and continued to attack him for seven years. After 2013, their aggression gradually decreased. Then, all of a sudden, in September of last year, after 17 years of experimentation, the crows no longer attacked or followed him when he walked outside wearing the same mask. He is now preparing to publish his research on this intriguing phenomenon.

Through his experiment, Professor Marzluff discovered that crows have a brain region similar to the amygdala found in mammals, which is responsible for processing emotions. He found that crows not only observe human behaviour but also recognize individual faces.

Crows have an amazing memory and can hold grudges against people they recognize as a threat. They can even pass on this grudge to other crows in their community. This can lead to some truly frightening encounters, like what Gene Carter experienced in Seattle. Crows watched him from his windows for nearly a year, making him feel like he was in a horror movie.