The other possibility is a spider. Their bites appear similar to mosquito bites, though they are slightly more severe (itchier, and they take longer to heal), and often occur in an irregular cluster of welts. I have been bitten more than a few times, though I am in North America. Perhaps it is more common over here. The best way to stop it is to find the culprit and kill it. Spiders like to come out in the dark, so if you walk into a room that has been dark for an hour or so, and suddenly turn on the light, you will likely notice it out there in the open (on the walls or ceiling). I once turned back the covers on my bed to find a spider sitting there on the mattress, "waiting" for me!! Now I look inside my bed before I climb into it, every time!! It has always been during sleep that I have gotten bitten. I think spiders like warm, dark places, like under the sheets.