Are you sure it's him? Black is a common color for cats. I was on another cat forum and there was someone who lost their cat and thought that they saw him creep around the corner of the house and ran away as soon as they opened to door to try and catch him. Later, he was found stuck inside a storage shed. So the cat they saw (it was nighttime) was likely a feel. I hope you find him soon! It's been a little over a month since my little boy has been missing. I miss him so much.