brown rat (Rattus norvegicus); common rat; dark grey; dark gray; deceitful employee; unfaithful servant
boards covering a ditch (drainage, sewage, etc.); grassroots (e.g. campaign); door-to-door; on the ground
to throw down the drain; to waste
ditch with running water; drainage channel
cleaning out mud from a ditch or drain
Sphaerium japonicum (species of fingernail clam)