A rumbly tummy is always a good sign that you need to get some food, but how do you know that you're hungry when you forage on behalf of a collective stomach? That is the problem faced by social insects. According to Elva Robinson from the University of York, UK, Temnothorax albipennis foragers are always the leanest occupants of the nest. However, ‘It's not as simple as the lean ants know when they're hungry and that triggers foraging’, explains Robinson, recalling that instead of consuming their honeydew load, slender foragers selflessly give it up to fatter nest mates. Robinson and her colleagues, Ofer Feinerman and Nigel Franks, wondered whether the skinnier ants forage because their mass has fallen below a critical threshold or whether the ants are motivated by their previous foraging experience and their slenderness is merely a side-effect of their frenetic lifestyle (p. 2653).