Most carpenter ant calls we take in Connecticut start the same way. The homeowner sees a few large black ants on the kitchen counter, brushes them off, and assumes it's nothing. Two weeks later, there are 20. A week after that, they're walking the baseboard at night, and somebody finally Googles "what kind of ant is big and black." That's when the call comes in.

Here's the part worth knowing up front: carpenter ants in CT homes are common, treatable, and almost never an emergency — but they should be handled before fall. They don't eat wood, but they do tunnel through it to nest, and a colony that's been active for two or three seasons can do real structural damage to sills, joists, and window frames. The good news is that one professional treatment, done right, almost always solves it.

This guide covers what carpenter ants actually look like, the signs that distinguish them from termites and regular ants, what ProSource's one-time treatment costs and includes, and why the 90-day warranty matters more than the number on the invoice.

How to Tell If It's Actually Carpenter Ants

Carpenter ants are large — a quarter to half an inch long — and almost always solid black, though some have a reddish thorax. The single defining feature is size relative to your kitchen-counter ants: if it looks two or three times bigger than the typical sugar ant, it's probably a carpenter. They have a smooth, evenly rounded thorax and a single node between the abdomen and thorax. Antennae are bent. Workers are flightless; the winged ones you see in spring are reproductives, called swarmers.

Most CT homeowners confuse carpenter ants with termites at first, especially when the swarmers appear. The fast way to tell them apart: termites have straight, beaded antennae and equal-length wings; carpenter ant antennae are bent at a 90-degree angle and their front wings are noticeably longer than the back ones. Termite damage produces visible mud tubes; carpenter ant damage produces small piles of fine sawdust (called frass) under wood voids.

Where they typically nest in Connecticut homes

Carpenter ants always nest in wood that's been softened by moisture. That means our New England housing stock — older homes with shaded sides, leaky gutters, deck ledger boards, and window frames that have seen 30 winters — is exactly what they're looking for. The most common nest sites we find are behind dishwashers, in window and door frames on the shaded side of the house, in deck ledgers, in the soffits above leaky gutter sections, and in roof valleys where ice damming has caused slow water infiltration.

Often there's a parent colony outdoors (in a stump, tree, or wood pile) and one or more satellite colonies inside the home. That's why simply spraying the visible ants rarely solves the problem long term — you need treatment that reaches the colony itself.

Signs you're past the early stage

If you're hearing a faint rustling inside a wall when the house is quiet, finding small piles of what looks like sawdust under window frames or trim, or seeing winged ants near light fixtures and windowsills in spring, you're past the early stage. At that point a single treatment is still effective, but it should be scheduled within the next week or two rather than left through the summer. By August, satellite colonies inside the home are at their peak size.

What ProSource's One-Time Carpenter Ant Treatment Costs

Our one-time carpenter ant treatment in Connecticut is $325 with a 90-day warranty . That's the flat-rate price for a standard single-family home in our service area, quoted upfront — no inspection fee, no surprise add-ons after the tech arrives. We can usually schedule within 24 to 48 hours, and most jobs are completed in a single visit lasting about an hour.

The treatment includes a thorough interior walk-through to locate the nest or nests, targeted treatment of active galleries and entry points, a foundation perimeter spray if exterior activity is identified, and a non-repellent product application around plumbing penetrations, sill plates, and any other suspect areas the tech finds during the inspection. Non-repellent matters here — repellent sprays scare the ants away from the treatment, while non-repellents are picked up unknowingly by foraging workers and carried back to the nest, eliminating the queen and the colony together.

When quarterly makes more sense than one-time

If you've had carpenter ants more than once, or if the property has known moisture issues, exposed wood, or a wooded lot, our quarterly Total Pest Coverage plan is often the smarter spend. It's $299 to start and $60 per month, covers carpenter ants alongside 15+ other pests, and includes unlimited call-backs between visits. Most repeat carpenter ant customers switch to quarterly after one or two incidents. We covered the trade-off in detail in our post on quarterly versus one-time ant treatments.

Why the 90-Day Warranty Matters

Carpenter ant colonies are sometimes split across multiple satellite locations, and even a thorough treatment occasionally misses one. The 90-day warranty on our one-time treatment exists for exactly that scenario. If you see activity in the 90 days after we treat, you call us, we come back at no charge — same-day or next-day across Greater Waterbury — and re-treat. We don't gatekeep this. There's no "we have to inspect it first to determine if it's the same colony" language. If you're seeing carpenter ants, we treat them.

This is also why it pays to use a company that's a phone call away and locally accountable. National pest control franchises typically book warranty re-visits two to three weeks out. We schedule them the same week.

What You Can Do Before the Tech Arrives

A few small things help us treat faster and more effectively. Don't spray the visible ants with hardware-store products before we arrive — repellent sprays scatter the colony and make the nest harder to find. Note any place you've seen the ants, especially after dark, and any moisture issues you're aware of (a slow leak under a sink, a section of fascia that's been weathering, a deck ledger that holds rainwater). Clear a small workspace under sinks and around suspect baseboards if possible.

If you find a piece of wood with frass under it, leave it in place if you can. A tech can confirm an active gallery in 30 seconds from that single piece of evidence and skip a longer search.

Book a Carpenter Ant Treatment

Same-day or next-day appointments are usually available across our 15-mile service area, including Waterbury, Southington, Cheshire, Prospect, Watertown, Wolcott, Naugatuck, Plymouth, and Bristol. $325 flat rate, 90-day warranty, no inspection fee.

Call ProSource Pest Solutions at (203) 405-9856 or request a free inspection online. If you're not sure whether it's carpenter ants or termites, send us a quick photo by text — we'll identify it before you book anything.