Had two rescue boys for over a year. Had to seperate them a few months ago due to sudden fighting, both looked to be doing well by themselves. Would have them out for a run at night and they'd still try to groom each others noses through the bars. Big male gerbils.
I always put cardboard in the cages. Toilet rolls, big tubes you get from Pets at Home. I decided to put the tube middle in from a bacofoil roll, cut in half so each gerbil had half each. Much smaller diameter to a toilet roll but far too small to get a head stuck? Not the case it seems.
I found one of my boys dead in his cage yesterday with his head firmly stuck and I feel absolutely devastated. Cried buckets yesterday and can't shake it. I would never, ever have put this in the cage if I thought this would happen. The other gerbil has demolished his with no problem. I just can't figure out how one of them got so firmly stuck.
We were out and about quite a lot yesterday and so I've no idea when this happened. The tube had been in the cage for almost two weeks. If only I'd just got it out.
He was the gerbil with the most personality. Always on the go. Extremely friendly and I'm going to miss him so much.
I keep reliving it and can't imagine a worse death, I really can't. I keep having thoughts of him stuck, struggling for ages. Bloody awful. We didn't tell ds how he died 
RIP my funny little critter 