Koala Hugs

My son is into koala hugs. I would be much more into koala hugs if he didn't weigh 60 pounds.
I'm not exactly sure how he came to be so interested in koala hugs, but I see how he's using them now. As our family has bounced about the globe over the last eighteen months, he has seen his friends and family slip through his fingers in ways that he can't control. And every night before his eyes close and he is transported back to the land of nightmares with deceptively even breaths, he clings to me, arms and legs constricting my body.
"Koala hug!" he cries. "Tighter, Mommy! Tighter! I can still breathe!"
Perhaps he imagines that if he holds tight, his grip can somehow control the uncertain world around him. I clasp him back. My world is as uncertain as his, although he'd never believe that.
And so we spend a few minutes thus entwined before bedtime, or before his brother comes for his koala hug. While my heart has room for them both, my back can't support the ninety combined pounds, and we tumble onto the bed.
How do koalas sleep? I wonder. Do koala babies have nightmares? More importantly, do koala moms have backaches?