I think the tiger its more usefull than the rat :)

Yes your animal kill the opponet animal if you animal attacks first and stronger.no matters the oppponents animal is on the trap.

yes if an oponnent animal its in your trap you can eat him with any animal dossent matter if is weaker that the animal in the trap.

In the jungle all the animals have a number the big number like stratego win over the small numbers, with an exeption, the rat can capture the elephant but not from water. like the spy in stratego can kill the number 1. only the rat and can kill the elephant and of curse the other elephant who atacks first.
Elephant (8)
lion (7)
Tiger (6)
Panther (5)
Dog (4)
Wolf (3)
Cat (2)
rat (1)

the tiger and the lion can jump over the water.