Only about 5 days later, the earliest 'pitters to hatch were already 4 or 5 times their original size and were now half an inch or more in length.

Taking care of them became increasingly demanding, with cleaning and feeding taking 90 minutes or more every day.

You have to keep their enclosure clean or they can easily get sick and die. Many of these very young caterpillars did not make it (most for unknown reasons) and their number dropped to about 60.

These guys are getting ready to molt, which they will do 6 times before they spin a cocoon and wait for Spring to emerge as beautiful moths.