Most female animals, Mrrzy, have to show willingness or the male can't have sex with them. If he tries anyway, he is attempting rape, I think, but he probably won't succeed.

Let me give you an example. I used to take care of rabbits. As is well known, rabbits have a lot of sex. ;-) That's mainly because the males never stop thinking about it! At any rate, a female rabbit will only consent to sex when she's at the right time for it, and she consents by raising her back end a little when the male mounts her. If she refuses to raise her back end, then he can't perform the act, though he may try mightily.

There was one young female rabbit in the cages who hadn't had sex yet, and apparently didn't want to. Maybe she was shy or maybe she was scared. I don't know. Anyway, she would not cooperate. A number of different males were placed in her cage over a period of 2 or 3 months, and she rebuffed them all, much to their chagrin.

The male rabbits all got obsessed with her. Finally my friend K-sahb who was an American Indian had a little talk with her. He told her that she better give in and mate with one of the male rabbits or we would turn her into stew meat. Later that day a male rabbit was put in the cage...and she cooperated! He got so excited that he nearly had a heart attack...

So, yes, many types of female animals can and do give consent. I can't speak for all of them.

I see no reason for legally banning any form of consensual sex for adults, as long as they do it in private.