But a quick search round showed up nothing amiss. I went back to sleep (eventually) and the alarm went off again. Three blasts, waa, waa, waa. Then quiet. Then again. What the hell was it? It sounded serious. It was certainly close by, in fact seemed to be coming from the caravan roof. Then I heard footsteps - on the caravan roof, followed by waa, waa, waa. It was a bird. Don't know what kind of bird. The kind with big lungs. Some birds mimic human sounds, parrots and the like, but this bird seemed to get his kicks from mimicking electronic sounds, and as far as I know there are no parrots in North Wales. This bird even seemed to posses some form of demonic intelligence, because it knew exactly the right time, just after I'd nodded off each time, to hit me with it's teeth-rattling siren blast.
Here's what I have learned: I know why farmers pack shot guns.