At the moment, animals tend to pack themselves together, especially when there are a lot of them in a small space. When they do that it makes it difficult to pet them or to milk them (if they're goats or cows). But the problem seems to be that no matter where I click or in which direction I'm facing, I always seem to select the same one. I think, although I'm not sure, the reason for this is because the hitbox for the animals is actually not on them, it's slightly below them which makes it difficult to judge where to click. My suggestion is that the animal hitbox be moved to a more obvious location, e.g. on the head or torso, so that this problem can be avoided.