This is a really sweeping statement. Some animals like jellyfish or corals do not have brains. Even if they are sometimes responsive to their environment, is that "perception"? Even if you think the answer is "yes", I hope you can see that it's not a trivial or obvious conclusion, and an unqualified statement about "all animals" may not be warranted.
Similarity with our own physical constitution? Similarity of behavior when we are in pain and they are in pain? And all the other cues that tell us that, indeed, they are sentient beings?
Ever watched someone work on a chickens feet that have a staph infection? Seems like the infection must hurt like hell because chickens won’t stand on it and limp around. Watching someone treat these infections you’d think chickens pretty much don’t feel pain. I don’t think your suggestion is as clear-cut as you think it is.
So you don't say that you percieve stimuli with touch, taste and pain receptors? Instead you should say that you sense it? I'm not a native speaker. That's why I'm curious about the distinction.
Yes, you perceive things you touch, because perception encompasses each and every sense. "To sense" does not mean exactly to use sensation. "To sense" can either be used as a synonym of "to perceive" or as a vaguer form of awareness. For example, you could say that you "sense danger" even when nothing is immediately threatening, if you can see various signs that all put together point to something being wrong.
