Can you bracket this boundary reasonably sharply? Say, mosquito: no, butterfly: yes?
No, but I strongly suspect that all Earthly life without frontal cortex would be regarded by my idealized morals as a more complicated paperclip. There may be exceptions and I have heard rumors that octopi pass the mirror test, and I will not be eating any octopus meat until that is resolved, because even in a world where I eat meat because optimizing my diet is more important and my civilization lets me get away with it, I do not eat anything that recognizes itself in a mirror. So a spider is a definite no, a chimpanzee is an extremely probable yes, a day-old human infant is an extremely probable no but there are non-sentience-related causes for me to care in this case, and pigs I am genuinely unsure of.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.