People have always been fascinated by the spectacular navigational skills of the humble bee. Years of research have revealed that these social insects use the sun, polarized light, terrestrial landmarks and odours to make their way home. Now, Antoine Chaffiol, David Laloi and Minh-HàPham-Delègue report that learning about a smell helps honeybees sniff out targets, such as a flower or their hive, at close range(p. 3731).
To confirm that odours play a role in short-range orientation in honeybees,the team tested the responses of single bees to odours in a wind tunnel. To see if bees use scents to home in on flowers, they wafted a common floral odour called linalool towards a bee in the tunnel and recorded circling and zigzag flight patterns, both tell-tale signs that the bee is orienting towards the odour source. To test whether a bee can sniff out her hive, they pumped air past the bee's nestmates and into the tunnel. Sure enough, the bees showed typical orientation flight behaviour with both the floral and the nestmate scents; they use odours to navigate at short range.
The team suspected that foragers use scents they encounter in the hive to navigate to a new food source. To test this idea, they conditioned bees to associate linalool with a drop of tasty sugar solution. When they wafted linalool through the tunnel, they found that conditioned bees showed more oriented flight patterns and found the linalool source faster than unconditioned bees. So, when a bee catches a whiff of a new smell on a nestmate in the hive, she's more likely to track down its source when she sets out on her next foraging trip.