Our gliders lost their cagemate yesterday. We know we want to have a trio because the enclosure just seems so empty with only 2 gliders in it. I want to be as responsible as possible about this. I know how to introduce because we have had to do that before. What I don't know is if age matters. Mine are 3 years old. They get along well we have never had a fight of any kind. The male is neutered and we have a female. Of course the next will be female as well. If we got a younger glider would it annoy my older ones with a "child" so to speak? I would think they would still be considered a young adult but would they be ok with a younger glider if they are all the same size? I have tried to find the answer and I can't find much on the topic.

Thanks!

Age is irrelevant, size and weight are more important.
It's not certain however that your gliders are ready to welcome a new arrival right after the loss of their cagemate, and new introductions always carry the risk to upset the balance of power of an established colony, so you can never really know beforehand how it's going to turn out.

Our introductions with smaller groups always went well.
We started have issues when going to 8 or 10 gliders.
We had 6 gliders together and added 2 more, one female of the six spent alot of the first few nights on the outside of the hammock pouch we used. The other 7 were happy. After the 3rd night the one female finally excepted things started sleeping in the hammock.

going to 10 we had one female that was very sweet and nice, although she wasn't happy ON us, just getting treats, and even was so nice letting us cut her nails even when she did not like being held. but in the new colony of 10 she was chased to much, then removed.

I think most of our introductions our gliders ages are 1 to 2 years old. Although one we had acted much older, but vet could not tell her age and owner before us did not know her age. she was just so slow and never jumped.

Thank you so much for the info. We will probably never have a colony of more than 3 just because I want to make sure I can give them the attention and care they deserve. I don't want to get to many and not do right by them. With 3 we can all play together, everyone gets attention and treats. They just seem to balance well. Our gliders have stopped looking for their cagemate and seem a little less active. The last day she was alive it was very clear she was sick so I think they knew. I don't know if they are depressed or not but thought maybe another one would pick up the spirits a little. We, of course, would bond with her and take the time needed to properly introduce like we did with their last cagemate. I just wondered about age since last time we introduced a new glider they were around the same age. I appreciate your knowledge and willingness to share it!