live until the following spring, at which time they awake from hibernation, mate, and then die. 

     Adults are sexually mature at hatching; their primary task is to mate and produce offspring. Adults feed on nectar from any available flowers. A captive Monarch will also eat dilute honey from a paper towel.  
     The summer's last generation of  monarchs, the ones that will migrate to Mexico,  are not sexually mature at hatching, even though they look just like normal adults. Exposed to shorter days and cooler nights, the developing larvae and pupae  undergo some alteration in their growth that prevents sexual maturation in the adult. When the butterflies are exposed to the lengthening days and warmer temperatures of the Mexican Spring, their reproductive organs begin to mature.