My son has autism. Yesterday, he said "I'm not trying to hurt you mom, bird just wants to come out". What does he mean by 'bird'?

My son has severe autism. He's non-verbal, and he doesn't make attempts to communicate with us. He's also self-destructive, and often hurts himself. We've gotten used to it, but the sight never gets any easier.<br><br>Last night, I was lying next to him and trying to comfort him when he started hitting himself. I held his arms and told him to stop, to try and calm him down. Then he said it.<br><br>"I'm not trying to hurt you, mom, bird just wants to come out."<br><br>My first thought was to correct him and say that he was the one hurting me. But when I looked at his face, I saw that it wasn't my son. He looked possessed.<br><br>I asked him what he meant by 'bird', but he just stared at me. I've tried many times, but he won't say it again. I don't think he even knows what he said. I just wish I knew what 'bird' was because whatever it is, it's living inside my little boy.<br><br>&#x200B;<br><br>Edit: There are lots of comments about how this could be a metaphor, and while I can't say for sure if it is or not, I think it might be worth mentioning that my son doesn't talk like that. When he does talk, it's literal. I don't think he would understand any other way of communicating, so I'm not sure where he would have learned about metaphors.