Common Spring Pest Problems In Denver, CO

Carpenter Ants

These wood-destroying insects are the largest type of ant in the Mile High City, measuring almost half an inch in length. Carpenter ants in Denver may be black or black with a reddish-brown thorax and only their reproductive members are equipped with wings. Though they are not economically important as termites, they are still not an ant you want anywhere on your property or inside your home -especially if water-damaged wood is present. Find out why moisture and carpenter ants are a bad mix.

Pavement Ants

If you’ve noticed ants multiplying in cracks in walkways, driveways, and other areas, the likely culprit is the pavement ant. Not surprising given its name, these small dark brown or black ants often establish nests in the areas mentioned above and while they’re not a threat like carpenter ants, they are certainly an annoying spring pest problem.

Sugar Ants

As we noted on our ant identification page, sugar ants are small brownish-orange ants that love sweets like the Golden Girls love cheesecake – in other words, a lot! To be fair, they will eat consume cooked veggies and munch on fruit. Though sugar ants nest outside and venture inside to forage for sustenance, they will infest homes and have been found in wall voids, under flooring, and around heat sources. As is the case with pavement ants, sugar ants are not a wood-destroying ant but fall into the category of nuisance ant.

House spiders

Frequenters of corners, crawl spaces, and undisturbed areas of homes, the common house spider is notorious for constructing messy webs inside and out. Though they are non-venomous and do feed on other insects, having an abundance of these spiders is an indication of the insect levels in or around your home. This type of spider varies in color combinations.

Wolf spiders

Unlike house spiders that spin webs to catch food, wolf spiders are more predatory, preferring to hunt their prey at night. This solitary spider is gray or brown in color and ranges in size from less than 1mm to 5-inches. Not a threat to human health, these spiders may occasionally enter homes but are considered shy.

Black widow spiders

As we noted on our spider identification page, black widow spiders in Colorado are venomous, but do not necessarily try to bite humans. Typically, spider bites occur during an unexpected encounter, but often require medical attention or at the very least a check-in with your family doctor. Widely-recognized by their black bodies and the red hourglass on their abdomens, females are approximately 1 ½ inches and males -about half that size.

Western yellow jackets

The Western yellow jacket, which accounts for over 90% of “bee stings” in Colorado, is a banded yellow and black or orange stinging insect that is quite aggressive when threatened.

Each spring, these ground-nesting pests establish nests in abandoned rodent burrows, behind brickwork, and behind stone walls. They will also build nests under porches and steps and inside wall voids.

Paper wasps

There are two types of paper wasp species residents of the Denver-metro should be aware of – the Western paper wasps and the European paper wasp (a newer arrival to Colorado). While both are more slender-bodied than other social wasps, they vary in color. The European paper wasp more closely resembles yellow jackets with their shiny black and yellow coloring. Western paper wasps are more reddish-brown.

While both types of paper wasps build paper, open cell nests, they do so in different locations. Western paper wasp nests are often found under overhangs of homes and buildings while European paper wasps establish nests in small cavities in the sides of structures, inside metal gutters, and inside grills.

Baldfaced hornets

Next up, we have baldfaced hornets. If you’re thinking we’ve put them in the wrong category, the truth is they are not actually hornets, but a relative of yellow jackets and other wasps. These large, aggressive stinging insects are often recognized by their coloring; they are black with a white pattern covering most of the face.

Baldfaced hornets build their nests at least three feet of the ground, usually in trees or shrubs, but also under overhangs and on houses, sheds, and even utility poles.