Residents often hire a pest control service to rid themselves of commensal rat issues but their accompanying ectoparasites can be overlooked. Tropical rat mites are commonly found among commensal rats within Alameda County, California. These hematophagous (i.e., blood feeding) mites are parasites of Norway rats and roof rats. Mite bites can reach an unbearable level, especially when their primary rat host is removed from a residence. They then disperse from vacant nests in search of a bloodmeal. Although these mites are not considered disease vectors, they can cause dermatitis and be a nuisance when they bite residents.