Mine don't work

U3A photographic meeting this morning - nice to catch up with people,  KG had a Cholesterol test booked for this afternoon so we didn't have lunch.  When he went down they told him he didn't need to fast for an afternoon appointment - now they tell us   When we got home we had a combined lunch and tea!!
We had some new battery powered Christmas lights with our tesco delivery yesterday
I put batteries in one set and then went off to do something else.
The elves had been sitting quietly on the radiator  THEN i heard voices

Elf said said Safety mine don't work 
Elf looked at him and said have you  switched them on?
Yes of course I have  Elf
Hmm Elf said - I was watching Mrs P and I think she had put in one set of batteries.
Does the make a difference Elf ? Safety asked
Well they won't work without them
At that I left them to it
A very bright and sunny afternoon but very cold