After finding the ants, you can drop them into the aquarium. That might be harder than it sounds. If the ants are really stubborn, you can place them into a refrigerator for a small while to cool down. After that they should be little less eager to run everywhere and you should be able to place them into the aquarium. Once that is accomplished you can just sit back and relax while your new ants do their work, the digging. It's surprisingly fun to watch them go around!
Ant aquariums can be found in different colors. Many have also some led illumination.
As usual, you can check youtube for: instructions, different colors and for some actual action.
-K-