We love comfy furniture with just the right amount of firmness, softness and warmth, and so do cockroaches. Something about their flat, smooth bodies makes them prone to snuggling into tight spaces where they can feel fabrics or other materials on their topsides and undersides. They like our furniture so much that they may hunker down and lay their eggs there, leaving hardened colonies of eggs ready to hatch in weeks, producing from tens to thousands of young progeny. Yellowed and whitish egg casings might be under tables and chairs of wood and plastics too. If you're OK with mass destruction, egg casings are easy enough to remove and destroy.
Even when not laying eggs, cockroaches have been seen proudly wiggling their antennae at the top of the couch back until running away at first light. And take care especially when bringing new furnishings home: Inspect for pre-existing eggs or travelling critters.