What started out as a nightmare last night, with a surprise happy ending - My dream started off where I actually was at the time, in my bed in the middle of the night. I'd just got up for some reason when I noticed movement in the sheets, a very quick, scuttling movement. It came across very much like it would in a horror film, with it not being clear at first if I'd just imagined it, then it building up to something frantic that I couldn't pinpoint what it was. I'd try pulling the duvet aside but there'd be nothing there, then when I stepped aside again the movement would start again. I pulled the bottom sheet back and was convinced there were rats in the mattress. I found a hole in the mattress with something scurrying inside it. I was scared that a rat was going to jump out when instead a dog stuck its head out. I stroked its head and helped it get out - it wasn't a puppy or a small dog, it was a huge thing about the size of a lab, that couldn't possibly have fitted in the mattress. It turned out to be friendly and was licking my hands when the dream ended.