People are being warned to seek medical treatment if they are stung by a wasp and notice any swelling, after pictures of large wasps nesting in Ħamrun were uploaded on social media.

The wasps, believed to be Oriental hornets, were spotted on the third floor of the Student Services Department in Fra Gaetano Pace Forno Street.

The wasps can be seen moving small stones almost their own size to make way for a nest.

The person who took the pictures said he contacted the local council, the government’s Għammieri farm, the Civil Protection Department and the Education Department.

The photographer contacted a private pest control company and was told that someone from the Students Service Department had got in touch but the company could not say when it would be going on site.

The post triggered a discussion on the Facebook Group Salott, which included suggestions of how to get rid of the wasps.

But others warned that these insects were dangerous. The Oriental hornet becomes more active as the days get hotter as it has the ability to harvest solar energy.

In fact, the hornets have a yellow strip across their body, and a special structure in their abdomen traps the sun’s rays while a pigment harvests the energy.

A public health official said people who get stung by a wasp should seek medical attention if they notice swelling or are in pain, or if they have been stung in the face.

If they are stung, people can try removing the sting with tweezers. If they are stung on their arms or legs they can apply ice.

Some people could get an allergic reaction and would need to seek medical attention as it could lead to an anaphylactic shock.

The sting could result in pain and swelling and they would need analgesia (painkiller) or antihistamines.