Do hens have fits?

I wondered if any of you have had any experience with a hen having what appears to be some kind of fit?  On two occasions now, one of my ex-bats, now about 3yrs old and otherwise healthy and fit, has come out of her coup in the morning, then gone under a bush or similar and started to make a strange crowing sound, a bit like a sea gull, shaking her head around, falling over, eyes closed, pale comb, seeming to be in trance like state, then after a few mins apparently making a full recovery and eating, drinking and flocking with her mates.  It happened for the second time this am (the first time was about a week ago).  By the time I had returned from going back inside to get a warm box to put her in, she had gone back into the coup and appeared to be resting.   A little while later she came back out and it was as if nothing had happened.   Very weird.

i would pop her along to the vet , just for a quick check over