Last night dp was rearranging the garden to allow for more space and he moved the dog kennels (3 of them!) from one fence to another. The h from next door came out and said a warning that his wife was not going to be happy about it in case the dogs were going to jump up and bark at their kids. His tone was contained but somewhat threatening. We obviously don't want this to happen, and equally don't want them to dictate what they can / can't do in our garden. They also have a dog, who is always peering over our fence (I've no issues with this). Today his child let slip that the neighbour on the other side had complained to them (not to us rather directly), that sand from a pile on our driveway (used for filling in / toddler proofing our pond) was 'getting on to our windows'. She said nothing to us directly. Both have made clear they will object to planning for an extension we are planning, even though both of their houses are way, way larger than ours.
What is going on? Why have they turned against us?