Lice can be species specific, so you probably wouldn't catch lice, but they are bigger, so you might see them. My guess is mites. You rarely see mites unless there's a huge infestation or you've got a bird that's not dust bathing - like a broody hen or weaker chicken. Either way, it's the same treatment. Although I do not see mites, I suspected it here.
For my birds, it started with poopy butt. (It's an orp thing.) As we washed each chicken, I noticed some had red skin and a couple had ratty-looking tummy feathers. Rooster feather damage is usually the head, back & sides of the hens. I know a couple people who are currently battling mites, so I suspect the weather this year may be the reason for the increase.
While my chickens were out in the yard on Saturday, I removed all the old bedding, feathers, spider webs, etc, then did a deep scrubbing, permethrin coop spray and DE after things dried before adding the new bedding. I also did lots of chicken baths and dusted them when dry.
TIPS:
* During/after the bath when the hen is wet, it's easier to inspect skin and feather shafts for mite damage.
* Chicken baths on a hot day help cool off chickens. Also allows you to keep chickens outside and prevents the need to blow dry.
* Easier to dust chickens at night and with a partner.