This video says about itself:
Up Close: Andrena Vaga Bee Digs an Impressive Hole
2 Feb 2014
Andrena is the largest genus in the family Andrenidae, and is nearly worldwide in distribution, with the notable exceptions of Oceania and South America. With over 1,300 species, it is one of the largest of all bee genera. Species are often brown to black with whitish abdominal hair bands, though other colors are possible, most commonly reddish, but also including metallic blue or green.
Body length commonly ranges between 8 – 17 mm with males smaller and more slender than females, which often show a black triangle (the “pygidial plate”) at the abdominal apex. In temperate areas, Andrena bees (both males and females) emerge from the underground cells where their prepupae spend the winter, when the temperature ranges from about 20°C to 30°C. They mate, and the females then seek sites for their nest burrows, where they construct small cells containing a ball of pollen mixed with nectar, upon which an egg is laid, before each cell is sealed. Andrena usually prefer sandy soils for a nesting substrate, near or under shrubs to be protected from heat and frost.
Andrena females can be readily distinguished from most other small bees by the possession of broad velvety areas in between the compound eyes and the antennal bases, called “facial foveae”. They also tend to have very long scopal hairs on the trochanters of the hind leg.
Some people say spring starts officially on 1 March. Some say 21 March. Astronomers say between 19 and 21 March.
Though it is still winter now according to many viewpoints, mild winter means that in the Netherlands, many birds and insects are unusually early, Vroege Vogels radio said today.
Andrea vaga bees are already flying. So are large earth bumblebee queens.
Some butterfly species fly already: peacock, red admiral, brimstone, small tortoiseshell. Not that surprising for these species, as they winter as adults, and will start flying when temperature allows.
A bit more unusual are other butterfly species which already fly now: small white and speckled wood. These species winter as pupae. Apparently, mild temperatures make for a quicker metamorphosis.
Skylarks and chaffinches sing already.