A rare butterfly which is milked by ants has been discovered at an East Anglian nature reserve.The silver-studded blue butterflies have been found at Minsmere on the north Suffolk coast.

A rare butterfly which is milked by ants has been discovered at an East Anglian nature reserve.

The silver-studded blue butterflies have been found at Minsmere on the north Suffolk coast. The RSPB has been working to recreate heathland on the site to attract breeding birds such as the stone curlew and woodlark. Now rare insects have been found, including the butterfly and 11 types of beetle.

The caterpillars of the silver-studded blue are picked up by black ants and kept in their colonies. The ants protect the caterpillars and milk them for a sugary substance until they turn into mature butterflies and fly away from the ant nest.

At Minsmere, silver-studded blues have been found for the first time on newly re-created heathland not far from existing colonies.

Heathland warden Mel Kemp said: "This is a great reward for years of hard work to re-create heathland. The heather looks fantastic in the summer, and it's great to see these lovely insects spreading into new sites after decades of habitat loss. This is an important contribution, not only for the survival of the silver-studded blue butterfly, but also towards the national target for re-creating heathland habitats"

During surveys of the new heathland, RSPB researchers found a beetle known as the Cockney, which had not been recorded in Suffolk since 1828. And they found 10 other ground beetle species that are classified as nationally scarce.

The silver-studded blue is also found on some North Norfolk heaths, and the Butterfly Conservation Society is working to reintroduce it to Cawston Heath. The butterfly was nearly wiped out in the county when the lowland heath it lives on was given over to farmland and forestry.