Tigger Ran Away...

This ain't good, my little buddy Tigger ran away... Me and Stephon were just chilling and having a drink, and then I went to let Tigger in. He usually just hangs around the house when I let him outside, but when I went to call and let him inside this time he ignored me and just ran up the street until out of site. Me and Stephon tried searching for him, but we had no luck. Now, we're just sitting and thinking of what to do. I guess my next step is to place a lost pet notice. Why would he run away though? I feed him, I treat him well, and I let him practically do whatever he wants. It just doesn't make any sense in why he would just run away like that.