Preliminary laboratory investigations of the feeding habits of seven species of ants occurring in southern Ontario showed that Camponotus herculeanus (Li.), Crematogaster lineolata (Say) and Formica exsectoides Forel are very predacious and will also eat dead insects. Myrmica americana Weber, Solenopsis molesta (Say) and Tapinoma sessile (Say) are also predacious, but probably because of the small size of the individuals and the colonies they are unable to capture large living insects. Lasius neoniger Emery, a relatively timid ant, may develop large populations and consume considerable numbers of other insects, but it is not recommended as a control agent because it can become troublesome on lawns.