I called Carlo last year when we noticed "sawdust" around the back porch and suspected carpenter ants that we actually saw running around.
Carlo confirmed, explained why (old damp wood) and sprayed thoroughly. He also said that carpenter ants are difficult to get rid off and gave us 1yr warranty. He came back once at the end of the summer to spray again.
We redid the porch this month, and while there was plenty of evidence in several locations that carpenter ants had lived there, they were gone totally and without doubt.
A few yrs ago Carlo expertly got rid of the vasp nest in our 3rd fl exterior wall, and carpenter bees in the railing.
He always answered his phone, or called back asap, and made an effort to come asap, too.
A nice guy and a perfect professional. While I am never actually happy to see him, I can absolutely recommend his company's services.