Drilling

So more and more over these last few days, I've been aware of a pretty loud drilling sound. I'm noticing it a lot at the moment, because I'm trying to write essays. The two African guys next door moved out yesterday, so I thought that maybe they had drilled something into the wall and were taking it off now. Or something. But I'm sure the drilling is louder now; I stepped out into the hall, and it sounds even louder; it sounded a bit like it was coming from above. So I went up to the 9th floor, but it actually seemed a bit more muffled there. I went back down to my floor, the 8th floor, and tried to locate the sound. It seemed loudest outside of Mohsin's door - he's the guy from Bangladesh who doesn't speak English very well; he's kinda scary, cos he stares blankly at you when you walk into the kitchen, and doesn't say anything when you say hello. Anyway, I knocked on his door a few times, trying to knock when the drilling stopped for a second. No answer, so I rang the doorbell (we have cute little doorbells here), once when the drilling was going (no answer) and then again when the drilling stopped - he did answer. When he answered, I noticed that his light fixtures were hanging from the ceiling in an unusual fashion, possibly because he had drilled out the screws. I said to him "Is... is that sound coming from your room?" I didn't really understand what he was saying, but he generally seemed to be saying no. Although, the drilling mysteriously stopped while he was talking to me, and started up again once I went to my room. It's stopped again now, but I don't know for how long. It's so difficult trying to work with noise that loud.