The female Peacock Butterfly usually lays her eggs on the under leaves of the Common Nettle in large nettle beds. Common nettle is a green plant with hairy-toothed leaves that sting and cause skin irritation if they are touched!

On occasions the female Peacock Butterfly lays her eggs on hop. Hop is a climbing and a self-twining plant with leaves that are heart-shaped and well-toothed. The leaves turn light green in the shade and turn a dark green in a sunny spot.

The female Peacock Butterfly also lays her eggs in damp places which get the sun. The female lays her eggs around midday in full sunlight. She can lay up to five hundred eggs which are usually laid in large and irregular batches. The eggs are spherical- shaped and a dull green colour. They are about one millimetre in size.

Caterpillars (also known as larvae) hatch out of the eggs within fourteen days. The caterpillars are cylindrical-shaped and have black shiny bodies which are covered with tiny white spots. The caterpillars also have long b$lack spikes along the sides and on the tops of their bodies. As soon as caterpillars emerge from the eggs, they spin a communal web for themselves. The web is formed from silk thread which is produced from organs next to the caterpillars’ mandibles (jaws). The silk thread gives caterpillars a good hold on their food plant and also gives them a place to rest when they take a break from eating. The caterpillars of the Peacock Butterfly usually eat a leaf collectively and then move onto the next leaf. Caterpillars may have a better chance of survival if they live and eat collectively.