The effect of constant light on maternal physiology and behavior

In contrast to previous findings in nonlactating rats, constant light does not disrupt maternal water or food intake. Mothers and pups in constant light, however, gained less weight than their counterparts in the light-dark cycle. While mothers did not differ in their total daily contact time or daily bout frequency, the distribution of the contact time was shifted in constant light. These data may be consistent with the idea that mothers maintain a free-running rhythm under such conditions.