Many thanks for all the replies.
When I was little, there was no trick or treating, but I remember going to bed absolutely terrified on Halloween
However, times have changed. I used to put up a "No trick or treat sign", but having seen the effort some of the small ones make and how much they seem to enjoy it, last year I relented!
Some good advice here, which I will heed, i.e put up a "Beware" sign, and also one making it (hopefully) clear that it's littlies only.
As mentioned previously, I have bought big bags of little bags of sweets (iykwim) and last year the children seemed to enjoy scrabbling for them when they were thrown (the sweets, not the children)
It seemed to be quite well organised, with all the mums and children going round in a group, so only 1 "visit" instead of being up and down like a whores drawers!
Also, they come round quite early, which helps. Locally you indicate if you are happy to be visited by leaving the hall light on or off, so once the smalls have been, the light can go off.
Fortunately when I have had to tell older ones that we don't give to them, there have been no "incidents"!
I will also post on the village facebook page, just to try to make sure that everyone gets the message.