Honey bees are an example of social insects that live in complexly organised societies. Investigating how these societies are organised has fascinated generations of researchers since ancient times, making bees one of the world's most studied insects. Since honey bees are also one of the few insects used by humans for various commercial as well as leisure purposes, learning about this insect allows us to improve beekeeping practices. To this end, and ever since the establishment of the Swiss Bee Research Centre (SBRC), researchers have studied not only honey bee diseases and pests and honey bee products, but also the biology of honey bees. Our biology research focuses on the topics of lifespan of individual honey bees, nutrition (including pollen consumption and honey storage) and colony development. In order to measure the latter for purposes of beekeeping management or for scientific ends, we have developed a method for estimating the size of colonies.