Of the Ants shown above, the Carpenter Ant is the pest we are most concerned with. They are larger among the ants shown, ranging from 1/8-1/2 inch long. Carpenter ants are being recognized by the structural pest control industry as the principal insects causing damage to structures in the northern tier of states in the U.S. and in southern Canada. They require a Wood-Destroying Insect (WDI) Inspection and more targeted Pest Control Methods.