Males of some groups of bees have to find a place outside the nests to sleep, sometimes forming "male sleeping aggregations". Here we report the first record of "dense" male sleeping aggregation of two different genera of Eucerini bees observed in Bahia, Brazil. We discuss the possible aim of this kind of aggregation as well the plant utilized on aggregate.
Keywords: Long-horned bees; Melissodes; Melissoptila.