Volunteers working in Cornwall say they have counted more than three hundred potentially deadly Portuguese man o' war on Portheras beaches.
The jelly-fish like creatures have a powerful sting, which can be fatal.
It comes after Perranporth beach had to be shut for a short time last week because of the creatures.
The RNLI says people should not touch the creatures.
If you are stung, Their advice is to seek assistance from the RNLI lifeguards on duty.