My suggies are vvery violent at night the boy crys all night and hisses and the girl doesnt cry but also hisses and it sounds as if they are fighting to the death at night. Its so loud. Is this how they play? what are they doing??

That doesn't sound very good. Were they properly introduced or just put together? Hissing is normal glider talk but it's usually not loud. Is it a loud and short "PSST!" or a slow hiss? Also what do you mean by crying? Barking or crabbing or crying like a joey? If they are fighting I would separate them! Are they perhaps trying to mate and maybe one of them doesn't want to?

Any idea how old they are?

mine r almost the same, i've seen them fight for less than 5 sec but they were together since born(both males).
but after awhile they r fine.. i am really confused to get worried or to let it be..

well i had the 1st one for like 3 months and i got the other 2 months ago. its not crying like a joey its crabbing. it is loud and they case eachother. i just put them together right away because the man i got it from said it would be fine.
They sleep together and groom eachother and seem to like eachother but late at night alomst everynight its like a battle

If you have a male and female, they could be either breeding or trying to breed. You dont have any idea how old they are?

I could be wrong but it sounds like they could be trying to mate. Usually the females crab a lot and run away from the male (which is a normal mating ritual). Is he climbing on top of her and biting her alot? They definatly make it really obvious when they are mating!

They could also be fighting over food..maybe have more than one eating area for them to choose from with the same food in the bowls.

Mine gliders are doing the same thing. The female is hissing and making a lot of noise but the male does nothing. She is only 3 months old and can't breed yet (or so I think). I believe they have to be at leats 7 months old. The male is 3 years old. I just put them in the cage together after being side by side in seperate cages for a week. I believe it's just the normal breeding action you are hearing and no harm is really being done. Watch them closely and maybe you can see what is truly going on.

ohhh thats a mating issue going on if they are male/female pairin. Mine do the same yet the female is pregnant with a joey and they still do the mating screams and all.

Gliderdad-your male will still try to mate no matter how old the female is...

yeah they will mate at any age i found this out myself with a young female and an older male