We use these animals in the following way: they can act as agents (a dolphin can defuse sea mines, a rat can smell a nuisance), they can also be suppliers (like pigeons to send letters).
2. I would also like to tell you about the dog's abilities. Dogs can work in the police, help in finding people or lost things.
3. Yes, of course they can, we have seen it in the examples considered.But I think that animals should not risk their lives for the sake of the lives of people who create problems for themselves.It's low and stupid.