Two deaths and a Weasel

Recently, I have watched some House Sparrows behaving strangely in the garden, scuttling about like voles across the ground. I managed to scoop up a juvenile. I presume it was sickening with something though their was nothing obvious to see externally. A few days ago my wife watched an adult male behaving in this way too, only for it to be snatched by a large rat that sprang out of the vegetation, dragging its squealing victim with it. As I was driving through Llanfihangel (Carms.) this morning I saw a group of about a dozen House Martins settled on the road in a tight cluster. I thought they may be warming up on the tarmac but as I approached in the van I could see that they were huddled about a dead Martin, a road casualty perhaps. A robotic response devoid of feeling? It didn't look that way. Also in Llanfihangel I was lucky enough to spot a Weasel. Not in flight on the back of a Green Woodpecker as in that astonishing case a while back but 'twas a Weasel all the same.