Brimstone Butterflies are one of the first species of butterflies to be seen in spring. They can be seen in gardens and meadows where there are lots of flowers. They are one of the longest-lived butterflies in England because they hibernate over winter, just like the Peacock Butterfly.

Brimstone Butterflies hibernate in large groups in hollow trees, sheds and attics.The male Brimstone Butterfly can easily be recognised by its sulphur-yellow coloured wings. It has an orange spot on each wing. The female Brimstone Butterfly has pale yellow or pale green wings with an orange spot on each. Sometimes the female Brimstone Butterfly can be mistaken for the Large White Butterfly.

Brimstone Butterflies lay their eggs singly on the leaves of buckhorn or alder shrubs. A blue-green caterpillar with a paler line running along the lower side of its body emerges out of each egg. The caterpillar forms a chrysalis by spinning a silk case around itself. Inside the chrysalis the caterpillar transforms itself into a beautiful Brimstone Butterfly.