From as early as the beginning of March to the end of May, dependent on weather and temperature, when queen wasps come out of hibernation they have the important and time-consuming task of establishing their colony as quickly as possible. For queen wasps this is a deadly race against time which most of them will lose.
Not only do they have to find nectar to feed themselves but they also have to find a suitable nesting place and start building their nests. Queen wasps fly low to the ground, searching for any round, dark object or depression. If it is a hole, they fly in to see if it is suitable and if not, move on to the next hole. This can be a void, crack or crevice within buildings.
When a typical queen wasp has found a suitable site for nesting, thousands of trips are required to collect wood which she pulps into mulch to build the nest. The first thing the queen builds is the foundations of the nursery. Even before the nursery is complete, the queen will lay several eggs to bring on her brood as quickly as possible. She will then continue to build her nest and the nursery around her first eggs.
All adult wasps feed on sweet liquids that are packed with high energy sugars. However, this changes when the eggs hatch into grubs. The grubs need protein to grow so the queen changes her behaviour. At this point she starts to hunt for other insects to feed her brood.
We start treating wasp nests from the end of June to October when the nests are large enough to locate and treat effectively.
(from BPCA article PestWatch Queen Wasps )