Bees, wasps, ants and termites are fascinating because of their well organized societies. Among the characteristics of social insects is the occurrence of a great diversity of exocrine glands. The high number of these glands goes along with the various functions their products play. To date, this variety amounts to more than 130 different glands that can be distinguished among the various social insect groups, with ants the most diverse group with 91 known glands. The glands can be classified in five main groups according to their anatomical organization. This talk brings a survey of the structural and functional diversity of exocrine glands in social insects, using selected examples that represent the main gland types. These examples at the same time also illustrate the big variety of functions the glandular secretions can play. A very well known function is that of producing the various pheromonal substances, that play a role in the communicative interactions between nestmates (such as alarm, trail, recruitment, sex pheromones…). Other known functions of exocrine gland secretions deal with reproduction and caste determination, or with the elaboration of antibiotic substances, digestive enzymes and saliva, nest material and lubricants.