Thousands of jellyfish have been appearing off the south Devon coast and on some beaches.
The jellyfish are about the size of a mussel
It is thought they are mainly of the "By-the-Wind Sailors" variety, from the same family as the Portuguese Man o' War, which can deliver a nasty sting.
Coastguards at Brixham are warning people not to handle the jellyfish, which are also known as Velella Velella and are about the size of a mussel.
They do give off a minor sting which may cause an allergic reaction.
Annie Westcott from the Brixham coastguard station said: "People are likely to see them. There are absolutely thousands upon thousands of them - people will think we're being invaded.
"They actually look like mussels from a distance because they are a similar colour, a purple-blue colour.
"We're just saying to the public, if you do go down to the beaches, don't handle them but we're quite happy to take reports about them.
"This is because the Natural History Museum has a big map and they are trying to plot where all these things are being washed up."