60 – 100 + Swallows feeding over the filter beds at cilfynydd sewage treatment works. There’s a plentiful and welcome supply of small flying insects on a cold on dreary day. There’s too many Swallows to count. A few sand Martins have also joined in with the feeding frenzy. I’ve just returned home and checked out the video I took, more like 150 – 200 Swallows.