Wiktionary
like a blue-arsed fly
a. (context simile English) To be frantic, harried or restless
Usage examples of "like a blue-arsed fly".
I've been chasing around like a blue-arsed fly since I left Tiptop.
It's a muggy night out there and I've been haring around like a blue-arsed fly, and I'm ravenous.
Zhlob just used to plod along, y'know, not buzz away like a blue-arsed fly.
I mean, we had a golem at S an' W's but ole Zhlob just used to plod along, y'know, not buzz away like a blue-arsed fly.
He was gunna be a real help to us, he'd been running around like a blue-arsed fly in some election they got coming up.