Cockroaches are distantly related to arthropods such as spiders (arachnids) and crustaceans (shrimp, crabs and lobsters). Cockroaches are insects (Class Hexapoda) and lobsters are decapod crustaceans (Class Crustacea). The term 'roaches of the sea' reflects the behavior of lobsters as omnivorous scavengers. Cockroaches will eat almost anything organic and so will lobsters. They clean up the dead and dying plants and animals in their environment.
Are lobsters and roaches in the same family