This is from the Oxford book of Greek verse. The author is anonymous and title is “Blind man’s buff”. Presumably this is what was chanted when you played the children’s game.
χαλχῆν μυῖαν Θηράσω.
Θηράσεις, ἀλλ’ οὐ λήψει.
I will hunt the bronze fly.
You will hunt but you won’t catch
Complete supposition on my part but I wonder if those being chased had to buzz like a fly.
The editors of the book date the verse to VII or VI century B.C.