Weevers (or weeverfish) are nine extant species of ray-finned fishes of the family Trachinidae in the order Perciformes, part of the wider clade Percomorpha.

During the day, weevers bury themselves in sand, just showing their eyes, and snatch prey as it comes past, which consists of shrimp and small fish.

The high number of bathers found on popular tourist beaches in these areas means stings are common, although individual chances of being stung are low.

The South Wales Evening Post stated (on 8 August 2000) that around 40 weever stings are recorded in the Swansea and Gower area every year,[6] but many victims do not seek medical assistance and go uncounted.

At first many victims believe they have simply scratched themselves on a sharp stone or shell, although this barely hurts; significant pain begins 2–3 minutes afterwards.

Common and minor symptoms include severe pain, itching, swelling, heat, redness, numbness, tingling, nausea, vomiting, joint aches, headaches, abdominal cramps, lightheadedness, increased urination and tremors.

Rare and severe symptoms include abnormal heart rhythms, weakness, shortness of breath, seizures, decreased blood pressure, gangrene, tissue degeneration[7] and unconsciousness.

Folklore often suggests the addition of substances to the hot water, including urine, vinegar, and Epsom salts, but this is of limited or no value.