I have loads of nats flying about in my garden but they don't seem to be in neighbors gardens can you tell me why this is and how can I get rid

Sorry that is nats not bats tiny black or green fly

Have you got a source of standing water in your garden - either a pond without a pump, or a bucket full of water, or anything like that? And are the gnats present all day or just towards evening, and always in sunlight?

Depends what kind of gnats they are but they are all decomposers. Some are herbivores, some carnivores, others like fungus. Look around to see if there's a dead animal's corpse on your property or rank vegetation; maybe a baby bird fell from the nest?

Sounds like what I call midges, all part of nature's rich tapestry and you don't need to do anything.