Which visual cue is commonly associated with carpenter ants?

The presence of sawdust or frass near wood surfaces is a prominent visual cue associated with carpenter ants. Carpenter ants do not consume wood but instead excavate it to create nesting sites. As they tunnel through wood, they push out the shavings and debris, which accumulate as sawdust or frass around their nesting areas. This characteristic is a clear indication of carpenter ant activity, making it an important sign for pest control technicians to identify when assessing for infestations.

The other choices represent visual cues that can be associated with different types of pests or conditions. For instance, wood chips near the foundation might suggest other wood-damaging insects or environmental conditions but are not specific to carpenter ants. Large holes in wood are often indicative of woodpecker damage or other wood-boring insects but do not specifically point to carpenter ants. Lastly, thread-like webs in corners are more commonly associated with spiders and have no direct connection to carpenter ant activity. Therefore, identifying sawdust or frass is critical for correctly diagnosing carpenter ant infestations.