The Case of the Vanishing Cockroach

Occasionally when I get home I'd see one or two dead cockroaches in the garage. Anybody that have seen my garage knows its dirty and old beyond repair. It's covered with boxes, newspapers, old tires and pipes, cement blocks, etc so it's not really surprizing if Remy's family is stirring up a stew in there. Being lazy and tired I'd leave the task of sweeping it away the next morning. Now the odd thing is that sometimes when I wake up the cockroaches would be gone. What does this mean? Did the rats or cats eat it? Was it really not dead but only pretending to be? Did the wind blow it away? I always wonder why the cockroaches vanish in the morning. Maybe there's a helpful garden gnome that cleans up my garage while I lay in bed asleep.