Peacock Butterfly Caterpillar's:
I first spotted them out the corner of my eye did a double take and leaned in to take a closer look, the writhing mass of little black caterpillars was quite fascinating to watch.
The behaviour of the larva is very similar to that of the Small Tortoiseshell, the two species often being seen together. In the first instar, Peacock larvae are very similar to those of the Small Tortoiseshell. However, mature Peacock larvae are jet black for the most part, whereas Small Tortoiseshell larvae are typically dark green with a pair of yellow stripes running down the length of their sides.
On emerging from their eggs, Peacock larvae build a communal web near the top of the plant and from which they emerge to bask and feed and are usually highly conspicuous. As the larvae grow, they move to new plants, building new webs along the way. Webs are decorated with shed larval skins and droppings and are easily found.
Larvae have several techniques to avoid predation. When disturbed, a group of larvae will often jerk their bodies from side to side in unison, which must be a formidable sight to any predator. The larvae will also regurgitate green fluid and will, if necessary, curl up in a ball and drop to the ground. Larvae feed both during the day and ay night. There are 4 moults in total