What could this be???

Duck was found on her back with her neck under her body.

Since she had this happen about 8-9 times (that I witnessed, and I'm mostly with her since the incident first happened) will be taking her to a vet today.

Each one of the 8-9 times it happened she would be limp and still for 1-2 maybe 3 minutes. And would have tremors after until she gets back to normal. She is also closing her eyes alot.

I was able to catch a video just a few minutes ago. Refer to my other posts here for more details.