Helpful animals

Crocodiles try to eat most birds that come near them. But one kind of
bird can walk about among crocodiles and be quite safe. In fact, these
birds even lay their eggs in the same place where the crocodiles lay
their eggs!

The birds are called water dikkops and they eat insects that bother the
crocodiles. Of course, this gives the birds an easy meal, but it also
makes the crocodiles more comfortable. So the birds are really helping
the crocodiles and maybe that’s why the crocodiles don’t harm them.

Other birds, called tickbirds, help the rhinoceros. A rhinoceros usually
won’t let other kinds of animals near it. But it lets tickbirds ride on
its back! Tiny insects on the rhinoceros’ back bite it and make it itch,
and the tickbird eats these insects. This makes the rhinoceros feel
better.

Little fish called wrasses help many other fish. Tiny worms often fasten
themselves to a fish and make sores on its body. When this happens the
fish goes to a coral reef where a wrasse lives. The little wrasse hunts
all over the fish’s body and eats all the worms.

The water dikkop, the tickbird, and the wrasse are all getting something
from the animals they help. They are getting food. And the animals they
help are getting rid of pests that bother them and cause them pain.
Scientists call this mutualism.