What if there were no bugs for baby swallows to eat?

On a warm summer evening, swallows swoop low over fields and ponds. Have you ever watched them zip and turn so fast that your eyes can hardly keep up?

Up under a barn roof, a little cup of mud holds a nest of baby swallows. Their parents zoom in and out of the barn all day long. What would happen if there were no bugs for baby swallows to eat?

Those zips and swoops are swallows hunting. A swallow catches flying bugs right out of the air, like gnats, flies and mosquitoes. Its short, wide beak is made for snapping up bugs in flight, and all summer long swallows eat nothing but flying bugs.

The baby swallows can't fly yet, so they can't hunt for themselves. Their mother and father catch bugs for them instead. Each parent squeezes lots of tiny bugs into a soft little ball in its throat and carries it home to the nest.

When a parent lands on the nest, every chick stretches up and opens its wide, bright yellow mouth. That bright yellow mouth shows the parent exactly where to push the ball of bugs.

Baby swallows grow fast, and growing takes a lot of food. Their parents fly back to the nest hundreds of times every day. Each time, another open yellow mouth gets a ball of bugs.

All those bugs turn into strong wing muscles and long flight feathers. After about three weeks, the chicks are ready to fledge, which means flying out of the nest for the first time. To fledge, a swallow needs wings strong enough to carry it through the air.

Now let's imagine a summer sky with no bugs at all. The swallow parents swoop over the pond and the field, but their beaks snap shut on empty air. What do you think the chicks will do when their parents land with nothing to give?

The chicks would open their yellow mouths wider and call louder and louder. But a parent with no bugs has nothing to push inside. The chicks would stay hungry.

Without food, the chicks could not grow strong wing muscles or long flight feathers. They would never fledge, because a baby swallow needs bugs to grow and to stay alive.

Fledge. Swallow parents can only feed their chicks flying bugs, so with no bugs the chicks would stay hungry, could not grow strong wings, and would never fledge.

Next time you see swallows zipping over a field, you can smile, because you know they are catching supper for a nest full of open mouths.