I looked on line, there were things like mice in the wall from people having cats chew - but I don't have mice so maybe bugs? Cats have keen hearing.
His mom abandoned him after the dogs found him and his 3 siblings in the runway, he decided to crawl thru the fence and I had to go get him to put him back with the others.
I put a blanket out as it was chilly at night and they were on wet ground.
Also left a bowl of food out for mom, she ate and took off with the other 3 kittens leaving him behind. So I brought him in.