“Who laid an egg like this? David, it's over to you.”

Imagine mine and Mr Swift’s excitement on returning home on Thursday evening to find not one but two eggs in the nest box! I’ll give you a hand conjuring up the mental image – picture a man and a women in their late 30s, jumping up and down in the pitch dark, asking a couple of chickens “Which one of you clever girls laid this?”

One egg was definitely Margot’s finest; 65g, mid-brown with slight speckling. Next to it was a small but perfectly formed 50g egg which must have been from one of the new girls (unless they’d shoplifted it from the Spar). Immediately photographed it for posterity then texted everyone with the good news. Dear God, just typing that makes me realise how tragic that was.

Only one problem with this tale of happiness – which girl had laid the egg?

I love a good mystery, so in true Nancy Drew fashion I set about hatching (ha!) a plan to identify the girl responsible. I figured the most obvious route would be to catch the hen in the act – Plan A. This was cruelly thwarted from the offset as only Margot laid on Saturday. Hmm, time for Plan B; analyse the new girls’ appearance and behaviour for any tell-tale signs. Both Barbara and Tomasina are exhibiting different, but equally compelling signs of being in lay. So that was Plan B buggered. Figured I’d start again with Plan A on Sunday.

This morning i let them out at 7am – no egg. Popped back to bed for a couple of hours only to check back to find another perfectly formed 50g egg. Marvellous - I find myself outwitted yet again by a bird with the brain capacity of a cheap digital watch.

Time for Plan C - the webcam.