Again, you put the assumption that an animal thinks like us, or rather, to have rights, it must follow the same laws and thinking we do. You are trying to place morals on an animal whose life is run, not by morals, but by simple requirements of survival.
The rights of an animal are imposed by us, are placed by our own morals - not the animals - and it lowers us as human beings to try to pretend that isn't the case.
Using the excuse that they do not understand their rights does not mean they are not entitled to them.