Mikaila Ulmer’s lemonade is now stocked in more than 500 stores across the US, but unfortunately she has slipped to a “C” in her maths class.

Running a successful business is very much a full-time job, but Mikaila – the founder and boss of Me & The Bees Lemonade – also has to make time for her school work. Just 13 years old, one day she will be in class, the next she could be speaking at an entrepreneurship conference.

“Sometimes I have to miss classes to do an interview, or travel for a TV show. Or I’ll miss a big show or presentation because I have a large project or test at school.”

Now selling 360,000 bottles of her lemonade a year, with stockists including upmarket supermarket chain Whole Foods Market, Mikaila is one of the youngest business owners in the US.

With the continuing help of her parents, Mikaila first started selling her lemonade in 2009. That year she set up a table in front of the family home, and began selling lemonade based on a 1940s recipe from her great-grandmother.

The recipe contains honey, and around the same time Mikaila got stung by two bees in two weeks. Her mother and father advised her that rather than freaking out at the sight of every bee, she should do some research to better understand them, and the crucial role they play in pollination, and the wider ecosystem.

This inspired Mikaila to give some of the money she raised from the sale of the lemonade to organisations that protect honey bees.