I decided they were bees - they looked like a blue banded bee but different...
I ended up sending a few pictures to Nick at Australian Native Bees and asking him what he
A. thought they were and
B. what he thought they were doing!
He said they were likely to be drones waiting for the mating flight of a queen in a nest somewhere - sort of a bee bucks party!
(Lipotriches Australica) - an Australian Native bee!
With both pieces of information I was able to search the net and find that even though I've only seen it twice, its a reasonably common occurrence.
From the Australian Museum website:
"Nomia bees live in urban areas, forests and woodlands, and heath. Most species nest in the ground and a number of females use the entrance and main shaft but dig their own tunnel off to the side.
During the day male Nomia bees forage for nectar but at night hundreds of them gather together, clinging onto grass stems. Nobody really knows why they do this but it is a behaviour that some other bees, including blue-banded bees, also show.
The behaviour of the females is slightly better understood. Up to three share a nest burrowed into the soil. They take turns guarding the entrance, blocking it with their face during the day and their abdomen at night. Inside the nest the Nomia bees make urn-shaped cells containing a disc of nectar and pollen and a single egg. Each nest may be reused by several generations."
a look at Robert Ashdowns blog... and read his story about finding a similar wriggling mass of bees on some grass here in Brisbane - click on a few of the links, the macro photos of insects is worth the side trip at the bottom of the post!
Nomia's seem to be quite a common bee across the globe and all seem to exhibit this bachelor party behaviour I found referances to this on sites across the globe! I spotted them here in Brisbane, both times in the late afternoon and even though I've kept an eye out for them every time I've been in the area since, I haven't seen them again. There must be more to this behaviour than just a sleeping place - or maybe they find a new place to sleep each afternoon....!
This is the grass clump that they were on. There are plenty of them around of the same grass species but they were all on this clump. I could kid myself that this was the same clump I saw them on last time as well. If not it was certainly in this area.
If you have seen Nomia bees - leave comments and links in the comments section - Id love to see your Nomia boys partying hard!