White bugs in pet mouse cage

Question
Four months ago, for my sons Birthday we bought him a pet Harvest Mouse, Peter. We cleaned him out once or twice a week, depending on how messy he got with his water & fed & watered him regularly. His little home was situated in the kitchen & he had a straw arch in there with a straw hammock/ball to sleep in. His bedding was made up of a recycled paper, specifically designed to be used as bedding. He shared the kitchen with our English Bullterrier who eats dry food that is kept in a storage container in the kitchen & our pet snake, Oscar that is housed in the dining room at the end of the kitchen who is fed on chicks & baby mice that are defrosted on top of his tank.
     Last night, I noticed Peter was lethargic & not his usual lively self. On investigation I noticed his little tank was overrun with tiny white little parasites, about the size of a grain of salt, on very close inspection they looked to have a tiny little hair to their rear. I haven't got a clue what they are or where they came from.... Peter seemed to be paralysed so I rubbed him down with alcohol very gently to kill any that were on him & put him in isolation so that none of the insects could get to him. I also cleaned his tank & got rid of all of his old bedding. I then held him all night to try to keep him warm but unfortunately he passed away at 3 AM this morning.  We are all upset. I can't help but to blame myself, that I wasn't vigilant enough to spot them sooner & that I didn't clean him properly. I am also worried that these bugs, any that may have survived will now infest my kitchen &/or my other pets.
   Have you any idea what they are? Where they came from? & if they can infest the rest of my kitchen & what precautions I can take? It's made me feel so dirty!

Answer
Dear Debbie,

After doing a bit of research (somewhat out of my expertise : ) ) I think I may have an answer for you. There is a type of insect known as a thrips (singular and plural are the same: both one thrips and many thrips). It is a large class of insects and some are white and the size of a grain of sugar.

Though searching under mouse parasites, I found more sources which linked them to snakes (people thought they came from the mice). Wikipedia describes them here, though not specifically those like what you found:

http://en.wikipedia.org/wiki/Thrips

Other hordes of white bugs that people have found around their snakes or mice are flour mites (rounder; red legs) or springtails (which jump around like crazy).

Here is the post that led me to thrips:

http://www.thamnophis.com/forum/garter-snake-lounge/4473-tiny-white-bugs-wood-sh

In any case apparently they multiply very fast, so just a few days without checking on him would be enough; and it would be easy to miss them when there were only a few.

Poor little fellow.

You did exactly the right thing to hold him all night. That can save a mouse which is fighting off anything, be it illness, poison, or in this case, parasites (anything where his immune system is compromised). It helps him to stay warm so he can use his own energy to survive instead of trying to keep warm; and it makes him feel loved. Loving mice often ask to be picked up when they know they are going to die, so you know he was in the right place to die as gently and peacefully as possible.

I'm so sorry about the little guy.

Oh- for control- just from my research and educated guessing, I would say they are not animal-carried and you should not expect a problem with the dog.  Apparently they can infest your home though- but since I saw that on an exterminator site, that may be exaggerated. I'll let you research that further.  As far as I can tell, they have nothing to do with anything being dirty. One person reported getting them from mealworms. It sounds to me like they may infest pet stores.

squeaks,

Natasha