Riddle with swallows

Children are given swallows to experiment with, as I read the riddle. The riddle goes:

"swallows are flying, how many are they

one has two (2) at its front

one has two (2) at its back and

one has one(1) in front and one(1) at its back"

Many solutions are recorded and at the end we read the solution beneath.

We keep it, for reference and play, in the mathematics corner:

They are only three(3), as the diagram above shows. The first one has two at its back , the middle one has one at its front and one at its back and the last one has two at its front.