FRUIT flies don’t just use light to synchronise their daily activities. They can also smell what time it is.
Light is the best-known trigger for setting daily rhythms, but many animals also rely on signals from others to coordinate their activities. The mechanism behind this isn’t well understood.
Now Jeffrey Hall, a geneticist at Brandeis University in Waltham, Massachusetts, and his colleagues have shown that odour cues keep the flies punctual. Air wafted from a group of insects was enough to change the waking pattern of an isolated comrade kept in the dark, while mutant flies that could not smell…
