Mice baby daycare
House mice often raise their offspring in a communal nest if they have similar litter sizes yet as soon as the litter sizes differ, there are fewer communal nests. The females want to lower their risk of being exploited. House mice are able to prevent social problems and still collaborate. These mice adjust their enthusiasm to work together based on the expected pay-off. Several mice mothers pool their broods in one nest and equally care for all young. The females apparently do not know which is their own babies and nurse all pups in the communal nest. To avoid disparity, the female with a smaller litter might kill some of the other females’ young to match the number of offspring. Females with imbalanced litter sizes were less cooperative. Therefore, the females adjust their inclination to cooperate to the risk of conflict and are more willing to raise their young communally if they have similar litter sizes at birth.
https://www.linkedin.com/pulse/mice-baby-daycare-randy-bilesky?published=t
http://www.delta-optimist.com/opinion/blogs/blog-mice-baby-daycare-1.2254388
