A small branch
You can do this skit as one act or bits and pieces as a running act between other performances.
The look-out, or sentry, comes running up to the camp fire director yelling “Lieutenant, Lieutenant, the Infantry is coming, the Infantry is coming, the Infantry is five miles away!”
Lieutenant responds with “Fine, keep me updated on the Infantry’s progress.”
Repeat this for three miles, then on one mile, then 1/2 mile, then 1/4 mile (or as many distances as you need to fill in between skits).
Then finally, the look-out comes running in holding the small branch yelling “The ‘INFANT TREE’ is here.
The ‘INFANT TREE’ is here.”