Sugar Gliders in the wild are very active creatures and need a high energy diet. They will often bite into various gum trees and rip off the bark to expose veins of sap which they will consume.

There are a lot of trees with Glider bites at the Ingleside Scout Camp (see example below). They bite through the thick bark of Red Bloodwoods (Corymbia gummifera) to make the sap run, then lick it for food leaving behind a mess.

Photo: Marita Macrae Source