For some years now, I have been reporting sighting of the first bat seen outside the windows of my flat in Edinburgh each year. Well today, just as it was getting dark, I saw a Common pipistrelle (Pipistrellus pipistrellus) or Soprano pipistrelle (Pipistrellus pygmaeus). I don’t know which species it is impossible to tell them apart in flight without a bat detector (The common pipistrelle uses a call of 45 kHz, while the soprano pipistrelle echolocates at 55 kHz).