Some kid showing off to his mates probably. So sorry LG, when you brought anything up from the first time it drew breath there is a bond there that's like no other. Hoping the other two pull through and you do find who it is. I would suspect your birds stay nearby in the main as it is food and shelter especially in cold weather. Maybe whoever it is will reappear for more 'fun' and you will catch them.
Had a lovely conversation tonight with Bailey's people, she is Horatio's litter sister. She looks like her mother and is so similar in her behaviour it's mind boggling. We were having a real laugh about it