Effects of urine from pregnant and lactating female house mice on oestrous cycles of adult females

Abstract
Mice treated with urine from pregnant or lactating females experienced longer periods of estrus than did mice treated with water or urine from singly caged females. Application of urine by perforated capsules placed in the cage of the test mouse showed that the factor(s) responsible for the longer periods of estrus was an airborne pheromone. The females experiencing longer estrous periods ovulated (ova in oviducts), became pregnant and gave birth.