That breaks my heart :( I talked to my biology teacher and he said it would work. Oh well this is why I was researching ^.^ Thanks so much for your answer!

I wonder if air circulation could be achieved with a fan?

Heard of people setting up tiny electric fans in their terraria somewhere before.

Speaking as a Biology teacher, your teacher is unfortunately incorrect. As has been pointed out, sealed terrs are typically very problematic in large part because of the issue of stagnant air. Few plants (or animals for that matter) do well under such conditions and fungi -- including pathogenic ones -- thrive.

Furthermore, vfts are EXTREMELY poor terr candidates for a number of reasons:
1) They are very high light plants ... even up to full sun. In a terr it is difficult to provide that kind of light intensity without raising the temperature to lethal levels.
2) Vft's like to send their roots quite deep. This would require a fairly large terr.
3) Most significantly, vfts REQUIRE a chilly/cold winter's dormancy to maintain health/vigor. Without it, they weaken and die -- though they may survive for two or three (maybe four if you are very lucky) years before finally kicking the bucket. Unless you plan on giving the entire tank a cold dormancy or digging the vfts up to do so, they are better off not setting a root tip in a terr.

Now having said this, some cps can be done in a "sealed" terr BUT it will require the inclusion of fans for air circulation and a rather large tank too. I say "sealed" in quotes because while the terrs in question are left closed for periods of time they are by no means left closed permanently. People I know growing Nepenthes, for example, this way, do open up the tank every day or two as they check on the plants and allow an exchange of fresh air.

It is far easier to go for a partly sealed tank setup (still using fans) as one can keep humidity levels up while allowing for some air exchange. With such a setup, there are a number of cps -- pinguicula, utricularia, and drosera -- that could be used.

With regards to the ant idea ... The concern regarding ants harming the plants is not terribly likely unless you were to obtain species that -- like the leaf cutter ants -- actually use vegetation as a food source. However, the issue of wet, stagnant conditions would prove detrimental to most ant species. Also most ant species are carnivorous or scavengers. So you would have to have present a renewable prey/food source for them. And unless you did have a very well sealed setup, you would in all likelihood have ants touring your room and/or home. (And I suspect your parents might object to that. )

For the last few days i've been researching ant formicariums, and such. I've been growing carnivorous plants for about 2 years I have a Venus Flytrap, a Sarracenia, and am currently growing Cape Sundews. The past few days, i've been having a few ideas of having a constant supply of food for my plants, and an ant farm seemed like a great idea. I've been wanting a Terrarium for my Carnivorous plants for the last few months, but have not had the funds to do so yet, I want a 20-25 gallon tank for the amount of plants I own at this moment (Sarracenia, probably won't fit in there after full maturity, but still). But, i've been thinking of having another terrarium, not quite as large, but large enough to have an ant colony. I was thinking about drilling a hole in the side of the ant terrarium and bridging it to the carnivorous plant terrarium with some sort of tubing, which could be blocked off with a cork or other object to stop ants from traveling to the terrarium with the carnivorous plants when I don't want/ need them to enter it. I live in upstate New York, and I realize that dormacy for the plants are very very important to keep their life span going for as long as possible, which could be prime time for the ants to repopulate ( Carnivorous plants only need to eat a few times a month so it shouldn't be that terrible of an idea). I don't know if this would work 100% but I would definitely not farm ants that eat plants, because that's the whole point of this, to grow my plants. But tell me what you think, I kinda like the idea, but am not educated on ants or ecosystems/ biomes enough to really make this kind of a call. Any tips/ suggestions would be greatly appreciated.

How would you put the plants into dormancy?

Drilling tempered glass can be very problematic as it tends to shatter. You'd have to do some research as to how best go about it.

Keep in mind all the issues mentioned above.

Dont know what might have to be done (if anything) to entice the ants to make the tube journey.

Be interesting to see what you come up with. Looks like you have a lot of research ahead of you. Keep us updated! (Probably be best to start a new thread for that.)