Koalas are most vulnerable (or at risk of something bad happening) when they are on the ground.
Koalas are totally made to live in the tree tops. Everything about them works best up there. Their arms are long and strong and their legs are shorter and weaker.
When on the ground they cannot walk upright, but their legs are not designed for walking on – think of what a dog or goat let and foot looks like.
Have you ever watched a koala walking on the ground? They look very awkward because it’s kind of like you trying to crawl but on your feet instead of your knees.
They can run very fast on the ground, but only for a short distance.
If they are on the ground then they often find themselves suddenly on a road, or they come across other big animals like dogs or livestock.
They also feel quite unsafe and stressed when on the ground and are always nervously looking around.
If they had lots and lots of trees, they would choose not to come down to the ground at all.