Its very logical. The current definition of sentience being proposed in the bill requires that an animal be able to perceive pain to be within scope (I'm not entirely convinced this should be a necessary condition, but that's what they've settled on) . When existing animal rights legislation was written lobsters, cephalapods etc. were considered incapable of doing this. The evidence now shows that they are capable of perceiving pain so they are being included in the bill (along with rats, deer and other mammals but not insects). Hence logical consistency is preserved. Perhaps the next time they revise animal rights legislation they will have evidence that insects can feel pain and so they will also be included.
