Those Butterflies

Parasites often choose very particular – and peculiar places to live. This crustacean invades a fish’s mouth, devours its tongue, and takes the tongue’s place. It then acts like a tongue; the fish can use it to grip and swallow prey.

Cuckoos are a special sort of parasite – they don’t live inside other animals, but they steal parental care. They lay their eggs in the nests of other bird species and trick the foster parents into rearing them.

Once a parasite has used up its host, it needs to escape.