Missouri Pest Identification Guide: Common Household Insects, Spiders, and Rodents

ID: Small (½ inch), light tan to brown with two distinctive dark parallel stripes running lengthwise behind the head. The most commonly encountered indoor cockroach in Missouri homes and commercial kitchens.

Behavior: Almost exclusively indoor pest; rarely found outside. Thrives in warm, humid kitchen and bathroom environments. Reproduces rapidly — a single female can produce hundreds of offspring in months. Gel bait is the most effective treatment; spray applications scatter populations and reduce bait uptake.

ID: Large (1½ – 2 inches), reddish-brown with a distinctive pale yellow figure-8 pattern on the back of the head. Missouri's largest common cockroach species.

Behavior: Primarily a sewer and basement pest that occasionally enters living areas. Found in basements, crawlspaces, utility rooms, and around floor drains. Its presence usually indicates a moisture issue or access from sewer connections.

ID: Medium-sized (¼ – ½ inch body), uniform tan to brown with a distinctive darker violin-shaped marking on the back (cephalothorax). Six eyes arranged in three pairs — unlike most spiders which have eight. Legs are uniformly tan with no banding or spots.

Behavior: Reclusive, occupying undisturbed spaces — wall voids, attics, basements, stored boxes, and woodpiles. Not aggressive; bites occur when the spider is trapped against skin. Bite can cause necrotic tissue damage in sensitive individuals. Common throughout rural Missouri and the Ozark region.

ID: Workers are small (⅛ inch), soft-bodied, creamy white with no eyes — almost never seen in the open. Swarmers (reproductives) are dark brown to black, approximately ⅜ inch with two equal-length wings that shed after swarming. Distinguished from ant swarmers by straight antennae, thick waist, and equal-length wings.

Sign: Mud tubes on foundation walls, piers, or exposed surfaces — pencil-width tunnels of soil and wood particles providing protected travel between soil and wood. Hollow-sounding wood. Frass is not typically visible — unlike carpenter ants, subterranean termites do not expel material from their galleries.

ID: Small (2–3 inches body), gray-brown, large ears relative to body, pointed snout, thin tail roughly equal to body length. Droppings are rod-shaped, approximately ¼ inch, with pointed ends.

Behavior: Enters structures through gaps as small as ¼ inch. Exploratory; forages widely from a nest site but typically stays within 30 feet. Nests in insulation, wall voids, and stored material. Snap traps baited with peanut butter are the most effective control tool; exclusion of entry points is the only permanent solution.

ID: Large (7–9 inches body), heavy-bodied, brown-gray, blunt snout, small ears relative to body, tail shorter than body. Droppings are capsule-shaped, approximately ¾ inch.

Behavior: Burrows in soil, under slabs, along foundations, and in crawlspaces. Rural properties near agricultural operations face elevated Norway rat pressure, particularly during and after harvest season when field habitat is disrupted. Significantly more wary than house mice; snap traps and bait stations require strategic placement based on activity sign.