They either lie-and-wait as ambush predators, maybe covering themselves with sand or otherwise camouflaging themselves, or move actively over the bottom in search for food.
en.wikipedia.org Attention was paid to reducing drag all rivets were flush headed and panels joggled to avoid edges but camouflage paint probably negated the benefit.
en.wikipedia.org Integral to mobility was elaborate camouflage and information denial procedures, such as restricting civilian movements prior to, or during an operation.
en.wikipedia.org In keeping with this camouflage, frogfishes typically move slowly, lying in wait for prey, and then striking extremely rapidly, in as little as 6 milliseconds.
en.wikipedia.org For survival, troops need warm clothing and footwear, extra nutritious food, white camouflage, tents with sleeping bags, heaters and fuel.
en.wikipedia.org