We have new neighbours

The tenants next door have 2 lovely young cats. One is a tabby, the other all black. They have taken to exploring at our place, coming through the back fence. As a result, I was in the garden the other day, when I heard a bell quietly tinkling. And there they were. The tabby is the brave and inquisitive one, the black one is nervous and more timid.
But they are kittens, so they're lovely.