Crows can hold grudges

Crows can remember and hold grudges against humans for up to 17 years. A study led by Professor John Marzluff at the University of Washington involved capturing and tagging crows while wearing a specific mask. Over time, crows associated the mask with danger and communicated this to other crows. The study highlighted crows' intelligence, including their ability to use tools, count, and hold "funerals" for deceased flock members. Crows also exhibit complex social structures and can teach each other about threats, ensuring knowledge is passed down through generations.