Sentimentalising is anathema, as far as I am concerned. It leads you into ethical problems about violence and killing and eating meat. The whole world becomes topsy-survy if you impose moralities that were evolved within human society on what a blowfly or what a parasite does... there are lots of emotions you can deduce from an animal's behaviour that are correct, but when you start saying it's feeling guilty or thinking or a loved one or mourning, you must be very careful of those feelings.