As if their lacquered looking shells and wings aren't creepy-shiny enough, cockroaches really seem to enjoy getting wet and being around water. Areas where pipes come into a home, through walls, floors and backs of cabinets, are often ideally damp and continually releasing bits of warm condensation for roaches to get their bodies into. Exposed pipes on walls also provide good hiding places, as do areas around washers and dryers.
Insulating and taping off gaps between piping and walls or false-cupboard and cabinet backing can help keep these areas dry and less inviting. Some areas where pipes terminate with a faucet, such as in the bathtub, may be harder to control. And cockroaches have no problem climbing up into open faucets and making dramatic drops into tubs and sinks to say "Hi."