Glue traps, I'm kinda pissed!!!

My 6 cats take care of the rats, mice, birds, baby birds, snakes, lizards, moles, whatever they find.
Problem with them is they don't always finish the job.
I've had to kill all of the above listed animals.
The method of putting them high over your head and throwing down on a rock or concrete is fast... I don't like to do it but when a baby bird is crying and it's little head is chewed on I have no choice.
I'm getting ready to leave the cats in the house for good or build a fence around the front lawn.