Ash is doing what some of us glider folks call the "Booty dance" Sugar gliders do this to mark their territories and their people and mate/ joeys.The male glider has both a head and chest scent gland. When Ash does what looks like a push up, he is marking with his chest gland and leaving his scent for other gliders to smell showing that this is his area. They will also rub their heads on their family, which can be quite a site as they dont do it gently. They grab eachothers faces and rub their heads back and forth. When your glider marks you, this is a good thing, and shows he/she is bonding to you and claiming you as his/her own. 

Gliders also mark their territories by urinating, and they will often mark people this way too. Just another thing to consiter before bringing a glider into your family.

Gliders do use their long tails in many ways but one of the most amazing things they do is to carry things in their tails. The videos show Tiger first tying his tail into a knot (this is a real knot which will then harden  to hold this position.) Next they push the item they are wanting to carry, in the wild: sticks, leaves and such to bring to their nests, but in these videos it is a straw. If you allow your gliders to play with straws, please supervise this playtime and remove them so the gliders do not eat the plastic.