Heat shock protein induction might be responsible for the longevity increase conferred by exposure to non-lethal stresses. To test this hypothesis, we studied in transgenic Drosophila melanogaster overexpressing hsp70 and controls, two behavioral variables (spontaneous locomotor activity and climbing activity) to evaluate the rate of aging, and life span. The results showed that in flies kept in groups, life span was decreased in transgenic flies compared to the parental line, but the contrary was observed in individually kept flies. Hsp70 overexpression had no dramatic effect on life span. Furthermore, we did not detect any advantage of Drosophila overexpressing hsp70 on the two measurements of locomotor activity. These results indicate that the rate of aging in transgenic flies is not different than in non-transgenic lines and that they are not more able to cope with the effects of aging on locomotor activity.