Early stimulation, parental behavior, and the temperature of infant mice

The effects of early conditions of rearing on parental attention and on the heat exchanges of infant mice were examined: (1) Inbred migce 6 days old were exposed at 7.5 °C and returned to the nest. Mice which were rewarmed before return recieved more parental attention then cold mice or handled Controls. (2) Outbred mice 6 days old with injured ears were licked more by there mothers then uninjured litter mates. (3) Liking of genitalia alos occured but was unrelated to ear injury. (4) surface temperature of 6‐day old inbred mice declined at after artifical “licking” with a wet brush. (5) Surfarce temperature of inbred mice exposed at 22–28 °C for 2.5 min. declined at age 0–11 days and increased at age 15–20 days. Exposure at 15°C led to a declined in surface temperature at all ages. (6) Wild or laboratory mice 4 or 6 satge old were observe in their nests. Surface temperature decreased after parental licking or loss of contact with the litter and increased on contact with mother. Temperatures also increased rapidly if the mouse was held on the experimentor's hand. in work on the effects of early conditions of rearing, attention should be paid to the minute details of parental attention and the heat exchanges of the toung animals.