Yes, stick insects need light to stimulate breeding and dispersion of eggs, but light also stimulates natural behaviour and feeding patterns. Newborn nymphs are attracted to light when they hatch, and it is believed that nymphs will use light as guidance to find the top of plants after they hatch to be safe and find fresh easy to eat leaves. However, within a captive environment, be very careful with direct sunlight. Although stick insects love a couple of hours of afternoon sunlight, keeping them in direct sunlight will quickly overheat the enclosure.