WHY WE DON’T HAVE A RAT-APOCOLYPSE

The Sigmodon hispidus are extremely “sexy” and will have up to 15 young after a gestation of only 27 days.  The babies grow quickly and will be ready to mate themselves in just 40-50 days.  A single female can have six or more litters per year.  If you do the math and assume a single female has six litters that each have five young… then that female can produce 30 offspring.  If half of those are females then the following year you have conservatively 450 rats.  I say “conservatively” because I’m not considering that every 40-50 days, each of the new females can begin mating!  So, why isn’t the world overrun by cotton rats?  You can thank predators, parasites, and diseases for fighting back the next rat-apocalypse.  Without population controls, the rats would become so numerous that they would eat all their food and starve.  A horde of skinny starving rats doesn’t sound pleasant.  I’m grateful for population controls.