The individual animals are called polyps, which are the anemone-like white stars projecting out of the shared (colonial) red structure. The red part of the animal can be compared with the concrete structure of a block of flats. The polyps are therefore like small apartments in the block, with individuals living in them, but sharing common services such as electricity, sewage systems etc. The polyps live just like anemones using their stinging tentacles to trap food from the water. This species usually lives much further south but is present at Lundy due to water currents coming from the Mediterranean Sea. Their small young (larvae) probably arrived in the same way as the sunset cup-corals and pink sea fans, ‘hitching’ a ride on the warm water current. When they have arrived and found a suitable place to live, the young settle onto rocky surfaces and grow into the adult colonies.