Since I assume you are playing on a smaller soccer field, and likely with fewer players, space can be a rare commodity with young children. Add that to the mental development stage that this age player is in, which says that most are still very self-centred and definitely NOT future-looking, and you can more easily see why they are all drawn to the ball.

First you have to get them to acknowledge that space exists! I find the easiest way to do this is to REALLY restrict space and let them feel what THAT is like. Try setting up a "field" that is about 20 x 10, complete with goals. Then play 6v6 (or some number that makes sense for your roster size). The idea is to make them operate in a VERY congested environment. After about 5 minutes, stop them and ask if this is easy. It probably won't be. Ask why. They will probably pick up on the fact that it is crowded.

Now, have them form a circle holding hands. The circle should be about 5 yards max across. Drop hands and put your "super defender" in the centre. You can even ask: "Who feels like a super defender today" and put that player in the middle. Give them a ball and ask the circle players to keep the ball away from the "super defender". The circle players cannot move. After a short time, stop them and ask the defender if it is easy or hard. It should be pretty easy for the defender. Now ask the circle players how they can make the defenders job harder. They should hit on the fact that if they had more space they could move the ball more easily. Have them take 2 big steps backwards and repeat. You should see a big improvement on the part of the circle players, and you should see the defender running much more. Have them take 2 more steps backwards (the circle should be at least 10 yards in diameter now, maybe a bit more) and repeat. Should be even easier, and the defender should be getting dog-tired. Talk again bout if it is easier or harder, and why.

Now, ask the players to take 10 big steps backwards. The idea is to make the circle at least 30-40 yards in diameter. Now repeat with a fresh defender. The distances between the circle players should be right on the edge of the passing distance of the players, maybe a bit more. Yes, this is dirty pool, but you need to have them actually feel what is not enough, as well as what is too much distance. This should fail, mainly because the defender should be able to intercept the pass. If not, have them move back until it DOES happen. Now talk about what size circle worked best for the attackers (the circle players) and the defender. Ask the players to try to help their ball-carrying teammate out by getting, and staying at that "perfect distance", of course in the proper support positions relative to the ball carrier (back-square, through).

Scrimmage on a "normal sized" field and freeze play when a good example of bunching occurs. Point out the "perfect distance" idea (not where the player is to stand) and let them move to where they think they can help the most. Resume play. Repeat as necessary. Also freeze play when you see a really GOOD example of support positioning, and point it out.