In warm weather monarchs make the passage from egg to butterfly in less than a month. Large caterpillars shred a leaf or two a day.
Both caterpillars, having molted four times, are 1.5 inches long and ready to enter the chrysalis stage. Filaments at each end are not antennae. One function may be to frighten flies seeking to lay eggs on the caterpillars.
Suspended from a silk pad it assembled on the screen of its cage, the caterpillar will hang in a "J" shape for many hours -- until itís time to become a chrysalis.