I would suggest buying the maggots and letting them pupate as I stated earlier. You can usually get them from cricket/feeder suppliers. I'd be a little concerned about possible pathogens and bacteria in free range flies, especially urban ones.
If you do decide to trap them, sugar water works well. There are even prebuilt flytraps employing sugar as bait. Unfortunately, they are also designed to drown them in the process. Most are configured similar to an inverted bottle with the entrance at the bottom and the bait suspended inside. The flies enter and can't find their way out.
WM
__________________
Revenge is a dish best served cold...
With a side plate of steaming entrails,
And a nice Bordeaux!
|