Here are more reviews. All were 5 stars except the last, which was 1 star. It never specified the type of animal. Critter Quitters are designed to keep out most tree frogs, rats, and snakes. Its possible a very small frog or snake could get through. It will not stop insects. However, the water in the traps should stop most of these as they are too small to swim through. Here they are

Oct 15
May seem higher priced than you expect, but is well made of very strong materials. When cut to your roof’s slope, it easily attaches to the stack and eliminated a repeating leakage problem we had due to our lead flashing being continually chewed by squirrels. I did use a band saw to make the cut due to the thickness of the material, but a hacksaw would work fine – just more slowly.

Oct 16
Oh, the squirrels are so mad. They fuss at me when ever they see me. Works perfectly. Easy to install.

Oct 16
didn’t stop animal from getting in again. But may work for other people.