Eagle-eyed observers have noticed the flying insects dead and stumbling around Australia's seat of government in Canberra.

Parliament's head beekeeper Cormac Farrell solved the mystery in a series of tweets explaining the bizarre bee-haviour.

"As the weather heats up, the nectar in some Australian flowers will ferment, making the foragers drunk," he said on Thursday.

"Usually this makes them a bit wobbly, and if they come back to the beehive drunk the guards will turn them away until they sober up."

Alongside a picture of a trio of motionless bees, Farrell said unfortunately they'd had a bit too much and died from the alcohol.

But he reassured apiary admirers the deaths were not due to pesky pesticides as almost none are used in the grounds around parliament.

Instead, Farrell is making the best of a sticky situation, reminding thirsty humans the sober bees' honey is used to make Parliament House mead.

"The drunk bees are kept out of the hive to stop the honey from fermenting inside, which could hurt the whole colony," he said.

"However, once the honey is finished, you can use it to make some wonderful alcohol."

Three beehives were installed at Parliament in 2017 as part of a bid to increase and protect populations in Australia.

Australian Associated Press