It's not a tough guy act, it's a defense mechanism because they can't show weakness or they risk getting eaten. Almost all animals do this, it's programmed into them.
Probing is not painful at all, same as getting a temperature rectally.
All life is important, no matter what kind of life it is.
All life is important, yes. Not all life has the same value, however. I would much sooner shoot a deer than I would a human. So if that is your REAL view on life, then you must cease to eat. Not even plants, because they're living things too.