Ethanol exposure during development promotes a series of neurobehavioral disorders in both humans and rodents. While in humans the deficits are most evident during childhood, in rodents most studies focus on the investigation of effects from adolescence onward. Considering that the examination of habituation at early ages provides a useful tool to assess learning and memory and its development, here we used the tail suspension test (TST) to investigate whether habituation of infant and adolescent mice is affected by ethanol exposure during the neonatal period. From postnatal day (PN) 2 to PN6, Swiss mice either received ethanol (5g/kg ip, ETOH) or saline (CONT) every other day. Mice were subjected to the TST for 6 min on alternate days from PN14 to PN20 (infancy) or from PN28 to PN34 (early adolescence). Only lateral (left- or rightward) movements with the torso were scored and used as a measure of activity. Differences between ETOH and CONT groups were observed during infancy. The activity decreased from PN16 to PN20 in the CONT group but did not change in the ETOH group. In addition, the averaged activity of the ETOH group was higher than that of the CONT group. No differences were observed between CONT and ETOH mice tested from PN28 to PN34. Our data suggest that the TST can be an important tool for the study of the effects of neonatal ethanol exposure in infant mice.