wilson456 I'm sorry to not address your question dirrectly. It depends on the location. My experience is that for small pests a .22LR is fine-particularly indoors. For mid-sized (coons, skunks, possums.... etc. a 9mms is a bit of overkill-but they often have rabies. For large ferral animals (large dogs, hogs....) a 9mms is mostly fine. For special pests it is marginal; grizzleys, rinos, buffalo, etc. The location matters as you may be prohibited from using a firearm or even killing them.
The same is true for poisions, the effective ones are often restricted to licesened pros. There are some available "natural" ones; but they require often esoteric knowledge. e.g. Goats are immune to botulism toxin and deer eat poison ivy, oak and sumac.
Traps may be successfully, but some jurisdictions restrict their use and getting the critter you are after instead of the cat or dog is problematic.
Booby traps and IED are a very bad idea as is gas.