Hatched caterpillars. Macrophotography footage of cabbage white caterpillars (Pieris brassicae) after hatching, ready to eat their host leaf. The leaf has been transilluminated. Cabbage white butterflies lay their eggs on a number of plants. The eggs hatch over a period of 2-7 hours, and the caterpillars then cause extensive damage by feeding on the host plant's leaves.