What has smooth galleries and small 6 sided pellets?

Drywood termites do and yes I found them under a crawlspace in downtown Mesa, Arizona.

Drywood termites are social insects that live in colonies in sound, dry wood. Each colony consists of offspring from an original pair (male and female). There are three growth stages – eggs, immatures and adults. Drywood termites are larger than local, southwestern subterranean species. Drywood termites tend to cut across wood grain destroying both the soft spring wood and the harder summer growth. Subterranean termites typically follow the grain of the wood, feeding primarily on the soft spring wood. Since they don’t live in the soil you must either get rid of the wood, if possible or fumigate. Some liquid treatments may work as long as the wood has not been painted or varnarished.