The ant Cataglyphis cursor is exceptional in that unmated workers are potentially able to lay both male and female eggs. We characterized eight pairs of primers for microsatellite loci, developed from genomic DNA for this species. Variability was tested with DNA from 19 workers and all eight loci were highly polymorphic, displaying 5 -10 alleles and a high level of heterozygosity. Cross-species amplifications indicate that these microsatellites might be useful in genetic studies of other species belonging to the genus Cataglyphis .

We used a maze to explore the ability of Cataglyphis cursor to store multiple visual patterns presented in a ¢xed sequence. Ants were trained individually to negotiate a linear maze that consisted of four boxes connected by tunnels and through which an ant travelled from a sucrose feeder back to its nest. Each box had one entrance and two possible exits. One exit led to a blocked tunnel and the other to an open tunnel leading to the entrance of the next box. The open and closed exits in each box were labelled by di¡erent solid, black shapes that were speci¢c to each box. Ants learnt to negotiate the maze using the shapes for guidance rather than a ¢xed motor strategy. Trained ants could not only discriminate positive from negative shapes, but had also learnt which positive shape belonged to which box. For example, when the positive shape appropriate to box 1 (1+) was pitted against that appropriate to box 3 (3+), ants preferred 1+ to 3+ in box 1, but chose 3+ over 1+ in box 3. We conclude that ants can identify individual positive shapes and expect to encounter them in the correct order independently of extra-maze cues.

Restricted reproduction is traditionally posited as the defining feature of eusocial insect workers. The discovery of worker reproduction in foreign colonies challenges this view and suggests that workers' potential to pursue selfish interests may be higher than previously believed. However, whether such reproductive behaviour truly relies on a reproductive decision is still unknown. Workers' reproductive decisions thus need to be investigated to assess the extent of workers' reproductive options. Here, we show in the bumblebee Bombus terrestris that drifting is a distinct strategy by which fertile workers circumvent competition in their nest and reproduce in foreign colonies. By monitoring workers' movements between colonies, we show that drifting is a remarkably dynamic behaviour, widely expressed by both fertile and infertile workers. We demonstrate that a high fertility is, however, central in determining the propensity of workers to enter foreign colonies as well as their subsequent reproduction in host colonies. Moreover, our study shows that the drifting of fertile workers reflects complex decision-making processes associated with in-nest reproductive competition. This novel finding therefore adds to our modern conception of cooperation by showing the previously overlooked importance of alternative strategies which enable workers to assert their reproductive interests.