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Peacock (Aglais io)

Surely everyone knows the peacock. It's common in woods, parks and gardens nationwide. But that’s largely because it’s such a stunner, with those azure-blue eye-spots lighting up its wings. And familiar or not, this butterfly is full of surprises.

Common name: peacock

Latin name: Aglais io


Caterpillars: black, white spots and with shiny black spines along back and sides.

They build a communal web near the top of the plant emerge to bask and feed. 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.

Adults: unmistakable, large, orange-red butterfly with spectacular, azure eyes on wings. The underside is almost black. Females are larger than males.

Look at one upside-down as it basks in the morning sun and imagine for a moment that you’re a potential predator, a mouse perhaps. Suddenly those piercing spots really do look like eyes, while the butterfly’s body becomes a beak, and the tips of its hindwings morph into owl-like ears. You’re staring down a rather scary enemy – especially if the peacock starts hissing at you, a trick it pulls by rubbing its wings together. All in all, you’re probably going to look elsewhere for your lunch. 

Wingspan: 6-7cm.

Food plants

Caterpillars: leaves of nettle, hop and small nettle.

Adults: nectar from a variety of plants including thistle, betony, bluebell, cuckooflower, dandelion, teasel and a particular favourite - buddleia.

When to spot them

March to October

Adults hibernate over winter and emerge on warm days. Mild spells can waken hibernating individuals in winter and early spring.

Where to spot them

Peacocks are found throughout the UK in a wide range of places including woodland and woodland edges, parkland, coastal and urban areas. 

Top Woodland Trust woods for peacocks

Good places to observe them include Clanger Wood, south of Trowbridge in Wiltshire, which also boasts rarer species including the silver-washed fritillary, purple hairstreak and Duke of Burgundy. Also check out Pen y Coed, at Llangollen in Denbighshire; Nut Wood & Wauldby Scrogs, near Hull in the East Riding of Yorkshire; Radley Plantation, outside Warrington in Cheshire; and Granllyn Pool, north of Welshpool in Powys.

Discover peacocks in other woods too. To find woods near you, type your town or postcode into our search box.

Fascinating peacock facts

  • Adults hibernate over winter - their wing spots help to camouflage them as they often huddle in groups in tree holes.
  • You'll also find them hibernating in garages, sheds and outbuildings.
  • Insect hibernation is called ‘diapause’.
  • If threatened they can produce a hissing sound created by rubbing the veins on their forewings and hindwings together – this is audible even to the human ear.
  • Peacock butterflies can live for up to 11 months.