I just got home from work and there was a mouse under the fridge 🙈 I don't want it to pass anything on to my rat boys but I don't want to put poison or traps down in case the boys accidentally get to it.
There's a method some people use with a bucket, a soda bottle, and stick. Grease the upper insides of the bucket, and put the stick through the top and bottom of the soda bottle and rest it on top. It makes kind of like a log rolling trap. I'm not sure what they're called. But put a little cat food or peanut butter on the middle of the bottle, and the mouse will (hopefully) climb up the bucket and onto the bottle. When it gets onto the bottle, the bottle will naturally spin from the weight and the mouse will fall off into the bucket (many people put water in the bucket to drown the poor thing, but that's really not necessary. You can just carry the bucked off and release it in a field somewhere).
If you do decide to kill it rather than use a catch and release method, just PLEASE do not ever use a glue trap. They are some of the most evil, inhumane traps I've ever seen. The poor things get stuck and probably absolutely panic the entire time until they are tired out, while getting more and more entangled in the glue, possibly smothering itself if it gets it's nose and mouth stuck. But if it doesn't end up smothering itself, it just ends up stuck to the paper unable to move until it starves to death slowly over days or longer. Really really terrible things!
A simple spring trap may be the most humane kill method, and it's easy to pick up up and move when you let your boys out.
Good luck, I hope you can find an easy way to catch and release the little guy!
I swear by the bucket technique myself--another variation is to simply balance a ruler on the edge of a bucket with more of the ruler inside than outside, and place a food item they'd go for on the end of the ruler. They run to the end of the ruler to get the treat, the ruler falls into the bucket under the weight of the mouse, and mouse falls in too. He's got a tasty snack to eat while he waits for you to come set him free.