What pipe openings???

when the builders cut a hole for pipes or wires to go into the home, often it is a little bigger than it needs to be and leave a gap around the edges.
that can be where bugs & little critters get inside.

usually under sinks and any other places where something goes thru the floor or wall..

Cats CAN be a good deterrant, when they want to be! LOL! We used to have 3 indoor kitties and when we got mice in the garage we would let them in there. I figured, hey, if the mice didn't want to get caught, all they had to do was go back out the same way they got in, no hard feelings. One mouse must have been exceptionally dumb, though. We came home one night to find a tail, JUST A TAIL, in the front entryway by the return air vent. The mouse must have popped out through the louvers right smack dab into the three cats just hovering there, as they were all declawed.

Recently, my DD age 5 was running up & down the steps to the bonus room playing pretend and talking to herself. I heard her say, "Oh, look at the baby mice! Aren't they cute?" and figured she was playing a new pretend game. Then she says, "Look Sam! There's four of them! Aren't they cute?" and I'm expecting to hear DS age 7 to say, "Erin, there's nothing there, stop bothering me." Instead I hear, "Oh, yeah, they are kinda cute." EEEK!

Somehow four baby mice had gotten trapped in the cat food container! I ended up letting them go in the field behind our house. But they cost me a brand new bag of prescription cat food!