Chick head twitch and yawning - something wrong?

[KLive]

Hi, I could use some advice. Our 17 day-old runt chick, a Golden Buff (Red Star) pullet, "Happy", has been doing this jerky head twitch (see videos below), but otherwise eating, drinking, pooping, running, jumping, peeping and sleeping. However, today she also started doing this regular hard yawning along with the twitching. When she arrived (from mypetchicken), she also had poo stuck in her bottom so I used forum advice and got the poo off and put a little apple cider vinegar in their water for a few days (that has now resolved). Her poo is a little runnier than the others, but not in a big way. We call her the runt because unlike the other chicks she still doesn't have a tail and her wing feathers are half the length of the others. I've seen a couple other people post about head twitching, but nothing definitive. Can you look at my video and let me know if you think we should take her to the vet, or so some chickens just do this? Thanks very much.

 

[KLive]

So the head twitching is getting worse. Every second. We are going to call the a vet tomorrow.

 

[KLive]

No responses to this, but I wanted to post a good news ending. Happy started to get better! I had taken her off apple cider vinegar for a couple days and she seemed to get worse, so I started putting it back in the water again, and she got better. She is fine now, and just twitches a little, and doesn't do the heavy yawning any more. Her poo isn't runny and bubbly anymore either. The 4 of them are 3 weeks old, so I put them all outside in their new coop during the day, and bring them back in at night. It is 80-90 degrees in MD right now, so they are pretty hot outside, but seem pretty hardy, and excited to be able to scratch around in the run.