The most common first sign isn’t a trail of ants it’s a small pile of what looks like sawdust near a baseboard, window frame, or door casing. That material is called frass, and it’s the debris carpenter ants push out as they excavate galleries inside your wood. If you’ve found it, the infestation is already established.
Winged carpenter ants called swarmers are the other major sign. In New York City, they typically appear in April and May, often on window sills or near light sources. Swarmers emerge when a mature colony is ready to expand, which means the original nest has been active long enough to produce reproductive ants. That’s not a new problem that’s a problem that’s been growing for years.
Some people hear it before they see it: a faint rustling or crackling sound inside walls, usually at night when carpenter ants are most active. If you’ve noticed that in your Brooklyn or Queens home and written it off as building noise, it’s worth having someone take a closer look.