If the colony is 10 years. It will be full grown (probably) and than there could be about 40.000 workers. Depending on a lot of things of course.
And have some problem more, I have give my ants over 4 flys, but they are still hungry? Why - because how much do they need. And I mean 4 flys on 2 days (: thx :D
Do they eat them or just leave them in the tube ? If your colony is only 10 workers strong they don't eat 4 (big) flys on 2 days. Maybe you could try something else, like a cricket.
Hmm, they eat all of the flys and them put it out from the tube, and they are ca. 10-20 workers (:
- But a day I'll try crickets.