There's a fine essay called "Crickets Bats Cats and Chaos " in a 1992
edition of Audubon (I'm not sure which one) that illustrates the possibilities
of animals and their conscious thoughts and the poor insight and understanding
we humans have on the issue.

I quit sport hunting a number of years ago because I could no longer
personally stomach it. I believe animals can and do suffer, and I believe I have seen them experience fear. It sucked.

Nevertheless, we have to take care of what we have. Does that mean letting
it go to the dogs (no pun intended) in the name of avoiding the suffering of possums, rats, cockroaches, gypsy moths, starlings, house sparrows etc. etc.?
Life is full of hard choices.

Values being what they are, I don't think there's a definitive answer to this . . .

Brent Ripley
brentr at hawlaw.com