Either that or it's a crow looking in and then as soon as it sees me move, its rapid eye movement lets it move out of the way in double time. But it has happened once or twice with someone being on the roof and he never mentioned to anyone about it before. I bet he's the type to burglarise his own tenants...he has telegraphed in the past that he enjoys stealing from people - he has actually admitted to stealing from people before! The stupid bastard!