Naked mole-rat mothers don't worry.
Most mammals follow the one-half rule.
That is, they produce about one-half as many young in each litter as they have mammae. In general, females have enough mammae for each young in the largest litters to have his or her own. It even works for humans, where our average litter size is one, but twins sometimes occur. Yet, there are no tantrums in the African burrows where naked mole-rats come from or in the popular zoo exhibits where most in the United States now live. We watched their nursing behavior and realized what's going on.