They do groom themselves. Trees grow a tissue around their wound. A chayote bends its vine on response to my touch. Yes they use chemicals and hormones to perform that action, but so do we?

Their nervous system is of course different and slower than ours, but you have no mechanism that would say you or cricket feels pain and my chayote does not. From my point of view you, chayote and crickets might all just be philosophical zombies and just respond to some stimuly as robots.