Pack rats reproduce year-round, but breeding always increases when environmental conditions are favorable and more young can survive. Freezing temperatures - fewer rats. Extreme drought - fewer rats. Nice mild weather with lots of vegetation from late fall rains - conditions perfect - lots of baby rats!
We are finding far more young rats in nests than typical for this time of year. These rats are still too young to be much of a nuisance, but soon they will be adults and breeding on their own. If conditions remain favorable 2012 could be a boom years for pack rats.