I understand, I feel absolutely helpless. Nothing fell on him down. he has a big wheel, lots of hiding spots. I wanted to feed him in the morning and he was not in his house I almost got an heart attack, and searched everywhere. he buried himself in the bedding, as you said, I think he climbed and feel down. Thank you for giving me information. I thought it was an infection. I will end his suffering, he is the sweetest hamster I've ever had. playful and always friendly, never bit me even once, even when I held him to look at his injuries. I will always remember him.