I bought some Cypermethrin from you guys about a month ago to handle carpenter ants. That in conjunction with some Drione that I had (thanks for your videos) took care of three nests and all was quiet. The past few days, I am starting to see some adults walking around aimlessly searching near where the nests were. There is no activity in the nests or their entrances. Would these be scouting parties from other nests looking to establish new colonies?

As explained in our CARPENTER ANT CONTROL ARTICLE, most all carpenter ant nests are networked to the surrounding environment. This insures their survival and why it’s imperative that all the “satellite” nests in any one network are either directly treated or baited to insure quick and complete control when treating for carpenter ants around your property.

Based on the limited information you provided, it sounds as though there are either stragglers or scout workers coming from missed nests that were part of the original network. If the activity is from stragglers, chances are high they’ll die off in a few days and disappear. And though you mention the CYPERMETHRIN and DRIONE DUST being applied, I don’t see any mention of bait like our MAXFORCE GRANULES or CARPENTER ANT GRANULES. Either of these should be used around the property to insure complete eradication so that if there is a local network nest in the area, it won’t be able to survive. Ants from that nest would undoubtedly forage toward the house as they have been doing in the past except that this time they would find the bait you have applied and die after some was ingested. That’s not to say the Cypermethrin won’t help control these foraging ants because many times it will. However, networked nests are slow to give up old habits and many times will keep trying and trying to find their old nests till they find their way back through an area where maybe the spray isn’t strong enough anymore. Once inside the barrier, they’ll attempt to start a new nest.

So in summary, I would say a Bait application outside the spray you’ve applied would be wise to do. If not, you’ll need to keep a close watch on the area to make sure the few ants you’re seeing don’t start a new nest or worse yet, that they are part of a nest you’ve missed. Leaving an active nest close to the home is a sure receipe for reinfestation.