Wild cats hunt wild things. Deal with it or call your local humane
society to humanely trap and relocate the animals. Poison is a terribly
painful and cruel death. Not to mention the fact that other animals may
eat the poison or the dead cats and get poisoned themselves. You could
find your whole section of nature damaged.
Mother nature has a delicately balanced ecosystem and she tends to get
pissed off when we go around poisoning things.

Is there no humane society (or animal control) where you live?

You can get horse tranquilizers and crush them into a powder, stir it
into a can of sardines and serve, or use my favorite poison,
antifeeze. I know from first hand experience both work extremely well.
You can also use a havahart trap to catch them and toss fiecrackers in
the trap with them, this terrorizes the cat and when released, will
not come around anymore. I prefer M-80s this eliminates the cat
altogether.

James Marz