What's the point of making a flute if you're not going to put it in your mouth?
Follow the bouncy ball, GSD recommended against the flute and provided an alternative instrument. One that you don’t put in your mouth unless you have an oral fixation.

But a flute is very involved and takes a deal of experience to make. Some easier ones to make would be a clacker out of Elderberry.
I agree with GSD on the flute, if you don’t know what you’re doing and just drilling holes in a hollow tube, you’ll have a hollow tube with holes in it. If you know what you’re doing and how far apart the holes need to be then go for it.
I like the clacker idea. Any kid can hand it off to another kid to play and create some backbeat rhythm with it. Simple to make and easy to use by others.