There are two specific reasons why cats regard your house as their home - one is territorial, the other concerns food routines. Cats place their scent on their new home, so wipe a soft cloth around your cats' faces to pick up their scent, and dab it around the house so that they recognise their own scent in the new house. Keep your cats indoors for about a month, and establish a set feeding time, and a routine telling them food is ready - tapping the dish for example. Before you let them out, withold food for twelve hours, then release them, but feed them about an hour later, using the set signal. Because they know food is a routine, they won't stray too far, and after a few weeks of this routine, they will connect their new home with feeding, and 'safe' scents, and their need to return to their previously familiar 'home' will disappear.