I feel like the default is that you aren't allowed to kill animals. Not as in most laws outlaw killing any animal, just that there are probably a lot of laws about randomly killing animals that aren't like tiny bugs and stuff. Like you can't just kill a deer unless you have a hunting permit. You can't catch fish without a fishing license. Sure, you're probably allowed to kill animals on your property that are a nuisance or anywhere in defense, but I wouldn't just assume I can kill a random animal.