The only test tube I've got that doesn't have anything in it is I think 3.5 inches long and at most half an inch in diameter(probably closer to a quarter inch in diameter. Is that a big enough test tube for up to 20-50 workers, a large brood and a queen? I think I've got either carpenter ant queens(which I know take up to a year to form a colony big enough to move into a larger formicarium) or Lasius neoniger queens on my back porch. In either case, I know they are a black ant species of some sort.
But yeah, I don't think that is a big enough test tube. Can I use a water bottle as like a bigger version of a test tube setup? It is a half liter bottle with these dimensions:
7/8" diameter opening
8.25" circumference at maximum
I'm sure that could hold more than 100 workers until I get a formicarium or make my own. And since I plan on getting a bearded dragon and breeding feeders for him/her months in advance, I'm sure that I will have enough feeders for an ant colony as well. And I'm sure the occasional wild caught bug won't do any harm as long as the bug does not live in soil and thus does not have velvet mites on it.