One Belfast man wasn\u2019t pleased to find that something extra had come with his recent fish purchase. We can see why: Upon preparing the sea bass for dinner, Rick Beattie discovered a large parasitic louse in its mouth. Beattie, who had purchased the fish at a Tesco location in Belfast, was promised a refund after he brought the incident to the grocery\u2019s attention. \u201cIt was like something from a horror film,\u201d Beattie said, according to SWNS.com. \u201cI\u2019m sure other Tesco customers would be interested.\u201d The parasite, known as the tongue-eating louse or Cymothoa exigua, enters a fish through its gills and attaches itself to the creature\u2019s tongue. Once in place, the louse destroys the fish\u2019s tongue, replacing it. The louse does not appear to hurt the fish in any other way. They\u2019re not believed to be dangerous to humans, although they can bite if picked up alive. A Tesco spokesman stressed that the company wishes to undertake an \u201can urgent and thorough investigation\u201d of the fish\u2019s supplier, Yahoo writes. \u201cWe have very high standards for food quality,\u201d he said. \u201cBoth we and our suppliers have robust checks in place to ensure that our food meets those standards.\u201d It has asked Beattie to provide the fish in question to aid the investigation.