I have several founding ant colonies set up in glass test tubes, with cotton ball stoppers holding back a few "inches" of distilled water --the "typical test tube setup."
After several weeks of sitting at elevated temperatures inside my makeshift incubator, the water is evaporating out of the test tube setups, leaving behind large pockets of air in the test tube where the distilled water used to be. Does anyone have any tips on how to refill these pockets of air behind the cotton stopper without disrupting the founding colonies within said test tubes? I don't really want to turn the test tubes in a vertical orientation when manipulating them (although maybe this is ok?) I'm guessing I may need a syringe and needle to inject fresh water into the water cavity behind the cotton stopper? (but I don't have a syringe nor know where to get one)
Is there some trick to making sure that founding colonies in test tubes get their water periodically refreshed without attempting to force the colony to move into a new test tube?