Activity in small mammals is affected by local environmental conditions. Shrews have high metabolic requirements for water, so microclimatic humidity should influence activity patterns. Six different B. brevicauda individuals were trapped and monitored for time spent feeding, drinking, out of a den area, and using a wheel in an experimental chamber for 48 hours under conditions of low (24%), moderate (60%) and high (86%) relative humidity. Time spent drinking was significantly higher in the high humidity level (P < 0.05) and was the only significant difference other than significant variation among individuals. High humidity may have reduced evaporation across the integument, causing an increase in heat load and stimulation of drinking behaviors. Other activity may not have been affected by humidity level because there was abundant, available food and water and no natural dangers. Additionally, the temperature was below the thermal neutral zone for this species, so there was no water loss due to active heat dissipation.