We have this stray cat that comes on our back deck that we feed. She recently had kittens(about 1 month ago). However she is a young cat and doesn't really have the maternal instinct to care for three kittens. Originally they would come up to the porch and let us pick them up and pet them. But then we gave one away and they haven't been back up on the porch in a few days. They are in the pipes under our porch. How can we coax them out?