Young hoglets do sometimes appear at strange times and a walk from one house to another can happen at any age. I’ve seen adults move house in my garden during the day then reappear at their usual time to go out for the night. It could be anything that disturbs them and persuades them to move.
With two hoglets living in the same house it’s more than likely that one of them decided he’d rather be on his own and legged it elsewhere. They certainly won’t stay together forever since hedgehogs really are loners except when ‘making babies’.
