It's not followed by a bark, just a long hiss, maybe 1 full second
He also does it when I move his fleece things around or mark them with my scent, leading me to believe it is an annoyed sound
He was also not kept with other gliders before, the breeder I got him from refused to split up gliders that were bonded together
In the same room as other gliders, entirely possible
Also, the room was not dark until noon, there were open windows
Shrug, I dimmed the lights at 10 and that's when he got up last night, he's asleep mow, guess things are back to normal :)
Leela, I just ordered a stealth wheel to go with the cage as well, I'm excited!