My female checkered garter I think has a neurological issue. I've seen it happen three times now. First time I saw it she looked like she was going to yawn then she opened her mouth and looked like she was trying to bite the back of her head, freaking out fast, lasted for 60-90 seconds.

The second time she kept her mouth closed and just nodded her head a couple quick times.

Third time it was to the side, she twisted her head quickly back n forth.

Each time it was a couple days apart. Mind you I don't stare at her all day. So it could be happening more then just a few times. She moves normal other wise.

I think I'm naming her Twitch