Hygienic behaviour of mite-tolerant Africanized and susceptible Carniolan colonies was evaluated in Brazil by sham-manipulating or artificially inoculating 4175 capped worker brood cells with dead Varroa destructor mites or ants, or their odour extracts. Both bee types expressed the hygienic components 'uncapping', 'removal of introduced mite/ant' and 'removal of brood' to the same extent and pattern. The similar response to dead mites of different origins and solvent-extracted mites indicates a minor role of scent or of movement of mites within sealed brood cells as releasers of hygienic behaviour. However, application of dichlormethane-extract of mites increased the hygienic response compared to pure solvent alone. Hygienic reactions to mite infested brood cells must, therefore, be elicited by other signals, possibly by the detection of specific reactions or odours of the infested larvae or pupae.