13. They use angry ants to their advantage
Some crows engage in a behaviour called ‘anting’, letting ants crawl over them or picking the insects up and wiping them across their feathers. The ants release formic acid in defence, which the birds spread through their plumage. There are lots of suggestions for the reason behind anting, including deterring parasites, soothing skin during moulting, making the insects more palatable and inducing a euphoric feeling.