If you've read Aleit's bio recently, you'd know that he is in a very odd mood. He's taken things more seriously than he really should have and is now nearly paranoid about everything.
So... when Aleit suddenly stops what he was doing and listens, he is looking for signs of anything that may harm the friends that are with him.

I know that there is nothing to worry about and that the forest just goes on, but Aleit thinks that as soon as he looks away, one of his friends will disappear. He also may act a little more possessive or defensive around his doe friends as he doesn't want any stags coming around to take them away where he'd never see/get to dance and hop around with them again. (But to the does with a mate, feel free to leave and be with your love, Aleit will just have to get over it CB)

His world has changed more than he wanted it to, so he's basically trying to rebel against the changes.

Remember, he's just in a weird state of mind right now, so it's best just to not worry. He's just a little confused.