whats the bar spacing on your cage? it needs to be 1/2 in or if you have joeys it needs to be 1/4in
As for biting it all depends on the glider. I have one who never bit me, another who nibbles, and i have another who was a pitbull biter.
they can break the skin and it can bleed. i recomend having bandaids and pain killers on hand. even when they dont break the skin it can throb for hours. Not trying to scare you, but its better to be prepared.
dont wear gloves to protect yourself for the bite, this does nothing for the bonding process. sorry to say but i believe its best to take the bite.