Kids climbing over fence

[upupandawa]

Not sure if I'm being unreasonable as I've never had this situation before. I live in a terrace house and my back garden backs onto other peoples back gardens so there's no alleyway/Guinnel between my back garden and the opposite back gardens. A few times now we've had balls coming over our fence from one of the gardens that backs onto ours, and the kid (maybe around 9 years old) climbs over our fence (6ft high) into our garden to get it.
I'm more than happy to throw balls back over when I notice them and know which garden they're from, this isn't an issue at all and I've always thrown balls back if I've seen one in the garden.
We recently replaced our fence and I'm worried about any damage it could cause having a kid climbing over, not to mention I don't like the idea of someone letting themselves onto my property without me knowing.
Also just to add, I have 2 large dogs who are naturally very protective of our home who go absolutely ballistic if they see him climb over and I'm worried about what could happen if my dogs are in the garden and he tries to climb over, they're not aggressive at all but would bark and jump up at the fence and possibly scare him.
AIBU to be annoyed by this?

YANBU. Go round and tell the parents.

You need to speak to the parents.

Don’t worry about the dogs. If they scare him he’ll stop climbing over.

Speak to the parents.

Knock on their door and explain the situation in a friendly way to the parents, for example, "Lovely to meet you, bit concerned about your son climbing over my fence, it's new but not laid in deep foundations and I'd hate for him to hurt himself if it came down. Please tell him I will always throw his ball back whenever I see it come over".

If they're even halfway decent people they'll be mortified and bollock him.

Speak to the parents - mention you have large dogs, and that you’re not sure how they will react to seeing children climb in the garden, they can be unpredictable when stressed. (Don’t say specifically they will attack, hint and let the parents fill in the blanks mentally that this isn’t just about protecting your property, but protecting their kids.)

That's not on at all. We get the occassional ball over from either side of us (fortunately cheapy plastic ones, not heavy footballs) and they always knock to ask if they can have the ball back - they don't even give into the temptation of using our side gate if we're out.