Mind the gap

The other day, a guy working on the neighbours' side of the fence asked if we had a dog. Suggesting we might want to keep an eye on her if she was out in the garden. 

At that point there was only a tiny opening at the bottom. "Don't worry," I replied. "She's too big to get through the gap." 

Now that I see what he had planned, I realise why he gave me a funny look.