The Invention Notebook

Nadia wanted to build a birdhouse that squirrels could not raid, because the squirrels kept stealing the seed she left for the birds. Her first birdhouse had a wide doorway, and a squirrel squeezed right in the very first day. Nadia was frustrated, but instead of quitting, she opened a notebook and wrote down exactly what went wrong.

For her second try, she made the doorway smaller so only birds could fit. That worked for the squirrels, but now the doorway was so small that the birds bumped their heads going in. She wrote that down too, along with a little drawing of the problem.

On her third try, Nadia made the doorway just the right size — big enough for a bird, too small for a squirrel. The birds moved in that week. When her cousin asked how she figured it out, Nadia held up her notebook. "I didn't figure it out at once," she said. "I wrote down every mistake until the mistakes ran out."