Scratching Occasional itching?

So, my family and I finally made our move to Michigan! It was a pleasant ride, and I made sure my boys (Hawkeye and Radar) were made as comfortable as possible for the trip. I gave them a warm place to snuggle, and kept them covered with an extra blanket to muffle noise and light for them - they were in a carrier, of course. They had plenty of hay and food for the trip, and I made sure to stop every couple hours to let them stretch, get some water, and some wet veggies to help keep them hydrated. Kept the temp in my car cool but not cold, as I knew their fleece blankie was a bit thick.

The first thing I did when I got home was set up their C&C cage (even though I was literally exhausted, my babies come first!). I have noticed, however, that they have been scratching somewhat off and on. It isn't persistent, and there is no hair loss or anything that I can see on their fur. (Radar is a bit longer haired, and I noticed a bit of spotty dandruff along his black hairs when petting him) Neither appear to be in any discomfort when handling them. If it continues, what are some warning signs that it might be mites/lice? Their bedding was recently washed - could it be the detergent?

Sorry if this seems like an ignorant question(s)...I just want to make sure I'm doing right by them, as I am a relatively new cavy slave (<6 months). Any responses are greatly appreciated, and I will keep my eye on them!