For nine months to a year, their habitat is the underside of a female lobster tail. Together with 10,000 to 100,000 of their siblings-to-be, these small, round, pine-green eggs ultimately hatch into pre-larval embryos and are released. After growing into gnat-sized larvae, which look much more like their bug-sized brethren than adult lobsters, they follow the light and swim up through the water column to their new home, generally within a meter of the sea surface.

During this planktonic (or floating) phase of their lifecycle, the lobster larvae that are not voraciously consumed by predators remain adrift for six to eight weeks, molting three times until they ultimately look like little lobsters. These mini-adults then bob around, searching for the right place to settle (literally and figuratively) and start their benthic (or bottom-dwelling) existence. Although they can survive in a variety of habitats, including eelgrass, salt marsh, or even mud (where they dig their own burrows), these choosy crustaceans actively seek out a cobble bottom with all its ready hiding places. The odds of a young lobster making it to the bottom are slim, however, with only one percent surviving to this stage.

For another five - eight years, juvenile lobsters hide and forage for food, seeking out areas with larger hiding places as they grow, such as cobbles, boulders, and other crevices. Ultimately, they reach a size that most predators can no longer tackle. Then they are free to wander the bottom with relative impunity, until they need to molt (i.e., shed their hard external skeleton so they can grow). Before molting, lobsters return to habitats that provide refuge from predators to reduce their vulnerability in this naked (and tasty) soft-shell state. Once their new exoskeleton hardens (a process that takes two weeks to a month) they are again free to roam. Seeking warm waters to improve their growth rates (and the growth of their eggs), adult lobsters commonly summer in shallow, warm, nearshore waters, migrating to deeper waters in the fall and winter when the cool air reduces nearshore water temperatures. Although much about lobster migration is a mystery, the distances covered can be dramatic, with studies finding that some lobsters travel more than 180 miles!

Such is the life of a lobster, moving up, down, and around—occupying different habitat at different life stages and at different times. And lobsters aren't alone. Coastal and marine species from anemones, to barnacles, to cod use different habitats throughout their lifecycles.