These leafcutter ants from Panama tend fungus gardens, which they farm for food. In a recent study published in Science Magazine, we found that the ants have specialised crypts on their body which harbour antibiotic secreting bacteria that protect the fungus garden against disease. Popularising articles on this can be found here (in Dutch) and here (in English).

The Indian ant Harpegnathos saltator. In collaboration with colleagues from Switzerland and the UK we studied the biomechanics of its jumping behaviour and the chemistry of some of its pheromones.

These Oecophylla weaver ants from Africa use their larvae to construct silken nests. In collaboration with colleagues from the University of Keele we studied the chemistry of some of their pheromones.

In the Malaysian ant Acanthomyrmex ferox we discovered that the large soldiers engage in spectacular "sumo wrestling" fights to settle the social hierarchy in the colony. Popularising articles on this can be found here (in Dutch) and here (in English).

These Australian bulldog ants have a fierce sting. In our lab we studied the ultrastructure of some of their pheromone-producing exocrine glands.

These army ants from Kenya form impressive raiding columns consisting of up to 20 million workers. In collaboration with colleagues from the University of Keele we were the first to identify the trail pheromone of Old world army ants.

A native black ant (Lasius niger) tending black bean aphids. In upcoming work we aim to study the ant-aphid mutualism in more detail.

This Finnish wood ant Formica truncorum forms impressive mounds. In collaboration with colleagues from Helsinki we found that the ants harbour maternally inherited Wolbachia bacteria. To prevent a cost to the colony, the bacteria are cleared in the worker caste, and retained only in the queen caste, through which they are transmitted to the next generation.

The Brazilian queenless ant Dinoponera or "Dinosaur ant". With workers reaching up to 3 cm in length it is the largest ant in the world. As in Diacamma, it has mated workers who take over the role of the queen. In collaboration with colleagues from Brazil we have studied the morphology of some of its exocrine glands and the chemistry of their secretions. We are also investigating several other species of queenless ant, to determine how they resolve conflicts in their societies.

In the Japanese queenless ant Diacamma, mated workers take over the role of the queen. In collaboration with colleagues from Paris and Japan we have discovered that workers mutilate younger siblings, and that this prevents them from mating. Current work is following up on this. For a popularising article on this in Dutch, check out this

The native Pharaoh's ant, frequently a pest in apartment buildings. Currently, we are studying the mating behaviour of this species.

The Brazilian stingless bee Melipona subnitida. In collaboration with colleagues from Brazil, we are looking at the conflict associated with the decision of larvae to become either a queen or a worker. Popularising articles on this can be found here (in Dutch) and here (in English).

The beautiful nest entrance of the Brazilian stingless bee Tetragonisca angustula . In collaboration with colleagues from Brazil, I am studying conflicts associated with caste determination. In some species, we discovered that larvae reared in worker cells may develop as miniature queens as a means to escape from an intended worker fate. A popularising article on this can be found here.

The native honeybee Apis mellifera. Currently we are studying the detailed morphology of the endophallus of honeybee drones, to determine whether its intricate and complex structure may have evolved in response to sperm competition.

The inside of a nest of the german wasp Vespula germanica. Recently, we discovered that workers in this species cannibalize or "police" eggs laid by other workers, in line with relatedness predictions. Two recent papers of ours in Science Magazine and Annual Review of Entomology review some of the work on policing in wasps, bees and ants.

A queen of the common wasp Vespula vulgaris visiting a Rhododendron flower. In an upcoming project we plan to use spring collected queens of various Vespinae wasps to look at the morphology of sperm in relation to variable degree of sperm competition.

The common wasp Vespula vulgaris. Kevin Foster discovered that workers in this species cannibalize or "police" eggs laid by other workers. Current work, in collaboration with the University of Keele, is aimed at identifying the pheromones used in worker policing in this species.

The native tree wasp Dolichovespula sylvestris often nests in bird boxes. In this species we discovered that when workers lay eggs, the mother queen frequently removes them. In this way, the queen keeps the workers under her thumb. A popularising article on this can be found here.

One we got into only recently, as a bit of a sideline - the Brazilian social spider Parawixia bistriata. It forms colonies of up to 1,000 spiders and constructs a giant web that extends over 20 metres.

A Parawixia spider sitting in the centre of her web.