Mouse suddenly hates enclosed spaces

Question
Hi, I've not been able to find any information on this and wondered if I should be worried? I have a beautiful little male mouse who's just over a year old. A couple of weeks ago he suddenly took to sleeping in his food bowl.  His little plastic mouse house which he's had since a baby and he spent many hours a day in has become not just unused but he actually seems scared of it and won't go near it even after being changed out.  We tried several new houses but he won't go inside anything all of a sudden?  Normally when we introduced new toys he loved things he could climb inside but how he seems scared of anything enclosed including tubes (which he used to love dashing about in).  Any idea why a mouse would suddenly act like this?  There's nothing that could of scared him and he's not frightened of being handled.  We've ended up putting bedding in various locations so he can move it around himself, it just seems odd after a year of being his favourite place that it now scares him? Ay ideas?  Thanks

Answer
Dear Julie,

Something happened when he was inside his house. It could have been something external like a scary loud noise or nauseating smell; or something Internal to his body such as severe and sudden pain. He now associates enclosed spaces with something bad. Mice are actually psychologically delicate like humans are, and they can suffer our same illnesses of the mind. Your mouse has PTSD.

Whether or not he will ever like an enclosed space again is impossible to know. However, it doesn't matter . Just give him a ton of nice soft bedding to make a nest of, or give him a nest "between the covers"-- I used to just give my mice a top blanket and a bottom blanket and they would make that their nest. Polar fleece is perfect bedding for small animals. You can buy a yard online for less than $6 and it may make him blankets for the rest of his life, assuming each blanket gets washed a few times before he chews it up. Another easy blanket is half of a sock, cut lengthwise.

Take the houses and tubes out for now. He might as well not have any reminders. In three months give him a toilet paper tube again and see if he will go in it. If not, he is fine without it. If he wants to sleep in his food dish, put something soft in it and give him his food in something else.

Let him call the shots. He knows what will make him happy :)

Best of luck and health to him.

Squeaks,

Natasha