Every water source in the garden is a great attractor on many of the nest building wasps that use the fluid in the construction of their nest. Digger wasps (Spheciformes) and Potter wasps (Eumeninae) use mud for the construction of nest cell walls and for the nest plug ^{[Spradbery 1973], [own observation]}. Pompilid wasps (Pompilidae) that use mud in their nest construction use the liquid as well to make the collected mud malleable, which is done at the excavation site where the material is found making it easier to shape it into a ball that can be transported to the nest more easily ^{[own observation]}. These solitary wasps do not tend their brood, but in social vespid wasps, that do, it is known that the foraging for fluids increases when the brood cells are occupied with larvae ^{[Spradbery 1973], [Matsuura 1990]}. From this last group it is especially the European paper wasp (Polistes dominulus) that is a very frequent forager of water on large easily accessible water sources in our garden.

Visiting some of these water sources is not without risks; a gust of wind or a momentary loss of grip or balance can be enough for the insect to end up in the water. That is what happened to this potter wasp female Ancistrocerus gazella ^{[Nederlands soortenregister],[Gereys 2016]} that I rescued from a vase with water in which it lay struggling.

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