The strangest thing just happened. One of my cats (the most twitchiest) was asleep on the chair and all of sudden he sprang several feet into the air as though something had majorly spooked him even though nothing actually had happened either inside or outside. He then went to look around and really looked scared and didn't want to be stroked.

He's not a new cat, we've had him for several years, we have Feliway on to de-stress him a little and as far as I know this has never happened before, so I was just wondering, do cats have nightmares or has anyone else seen this phenomenon?