What is this fuzzy creature? Sadly, it's not pettable. This is a microscope image of a fruit fly embryo, showing the individual cells within it. That's 2,458 cells, to be exact. The bottom image shows each cell in a different color, with lines to show how those cells moved around.
The image comes from a new technique scientists developed to watch every single cell in an early embryo and record what it does. Where does each cell go? When does it divide into two cells, and where do each of those two cells go? How do genes control what cells do? These are some of the most basic questions in biology.