A baby cockroach is a wingless nymph, 1/8 to 9/16 inch, usually dark with a pale stripe down its back. It usually means roaches are breeding indoors. Confirm with $10–20 of sticky traps, then bait.
Mostly, yes: house mice peak after dusk and again before dawn, and rats come out at dusk. Set traps before dark and check them each morning. What a daytime sighting means.
Cockroach poop is pepper-like specks from small roaches or ¼-inch dark pellets with flat ends and ridges from big ones. Wipe it up with hot soapy water, then set sticky traps to see if roaches are still active.
Often, but not always: one mouse can wander in alone. Fresh droppings, flour-patch tracks and 12–24 snap traps (about $14–27) show how many you really have.
Pantry moths are about twice as long, gray and copper, and fly around the kitchen. Clothes moths are tiny, plain gold and hide near wool. Each lure attracts only its own kind, so buy one $10 pack of the right trap.
Pepper-like droppings, egg cases, shed skins, a strong odor and roaches out in daylight. One adult on a sticky trap usually means a newcomer; nymphs of several sizes mean an established infestation.
Most "water bugs" in a house are oriental or American cockroaches from drains and damp basements. A true water bug lives in ponds, has pincer-like front legs and tiny antennae, and doesn’t breed indoors.
Mice sound like light scratching, scurrying and gnawing in walls and ceilings at night, with the odd high squeak. Rats are louder. Confirm with droppings, then trap nearby.
Rarely. A house mouse stays within about 30 feet of its nest, breeds year-round indoors, and cold drives it in, not out. Trapping plus sealing runs about $57–71 in supplies.
Roaches smell musty and oily, from droppings and secretions, and you usually notice it only in a large infestation. Trace it with $10 of sticky traps, then bait and scrub.
A wood roach is a native outdoor roach, ¾ to 1 inch, with pale edges behind the head. It can’t breed indoors and dies within days, so pick it up and toss it. No spray or exterminator needed.
House gnats don’t bite. The biting “gnats” are outdoor flies: biting midges at dawn and dusk, black flies by day. Long sleeves, a fan and a $6.99 repellent stop most bites.