A wheel well inspection on the ramp prior to departure does not assure that someone can't get aboard later.
Desperate people who climb into wheel wells usually climb airport perimeter fences and position themselves at night beside the taxiways. Four years ago two young males had crowded into the nose wheel well of a taxiing DC8 en route CLO-MIA. Both had received fatal injuries during incomplete nose gear retraction and subsequent nose gear collapse after an air turn back to CLO.
