Cattle egrets (a type of bird) are typically found around cattle and horses as they graze in the field. The cattle stir up various insects in the fields that the egrets feed upon.

I'm not sure what ecactly you are looking for but I'm thinking the word you want is symbiotic.

write the whole sentence and answer the parenthesis as well

So basically you copy the same sentence but you put something in the blank spot like symbiotic and you explaine why(in the parethesis) you know. and instead of saying boxer crab you would write Cattle egrets.

Both have benefited.