I have always enjoyed ant farms. I wanted an inexpensive, classy one that I could hang on the wall and that would not allow escapes. This fit the criteria!
You will need:
Two dollar store or second hand picture frames of exactly the same size with the glass inside
Step 1: Caulk the Frames
Carefully break the top of one of the frames off. This wasn't too hard with the frames I used. This piece will be the lid. (In the first picture I accidentally broke off the side too, so I just hot glued it back together.)
For the frame without the top, take out the glass, put caulk around the frame where the glass was touching (not on the lid piece), and put the glass back.
For the intact frame, you will need to do the same thing, but also put the hanger in place. Conveniently, my picture frames came with a little metal hanger that I bent into a suitable shape. Caulk the hanger underneath the lip, so that it is sticking out on the side where you would normally see the picture. Make sure there are no gaps in the caulk, or the ants will escape. Let dry for 30 mins, or as long as the caulk instructions say. Make sure that the hanger is securely attached, as it will be holding a lot of weight. (If anyone has any ideas for a more secure way to hang the frame, please let me know.)
Now, caulk the back of one of the picture frames (don't get it on the glass if possible) and stick the other frame on top. You have just made a picture frame sandwich that will hold the ants. It should be water tight. You may need to go around the edges and add more caulk if there are any places that need it. Let it dry.
Step 2: Make the Lid
For the lid, I cut two popsicle sticks to the width of the frame and taped them together. I wrapped some thin packing foam over the stick (leaving one skinny side bare) and glued it into place with hot glue. I glued the foam-covered stick (the bare side) onto the lid piece of the frame so that it would fit snugly into the ant farm opening. I jammed two small foam pieces into the sides to make sure that there were no spaces the ants could escape in.
The main idea is that the lid needs to seal shut using the foam.
A lot of people worry about insects getting enough air. I have never had an ant farm suffocate, but I have had several escape. If you take the lid off once every day to drop in a crumb and squirt a few drops of water, the ants will have plenty of air. If there is a hole, you can be pretty sure the ants will escape through it.
Step 3: Fill With Sand or Dirt
Time to fill it up! In the pictures I just dumped a bunch of sand in and then the dirt with the ants in it on top. You could make some pretty layers of different kinds of dirt and sand; I thought of it a little late, and I only need one ant farm at a time. Pour in just enough water to dampen the dirt and/or sand. You may also want to include a sprout of grass or other decorations at this time.
Step 4: Add the Ants
You can either buy ants online, in which case they will come with instructions, or you can dig up an anthill. I had an anthill in my backyard, so I decided to use it. I live in an area that doesn't have fire ants, but I hear that those can be nasty, so be careful of what type of ant you try to collect.
If you dig up an anthill, I suggest shoveling a few scoops of dirt and ants into a ziplock baggie. Put the baggie in the refrigerator (not freezer) for 10 to 15 minutes. This will slow the ants down. Take your ant farm outside and take off the lid. Cut a hole in one corner of the baggie with scissors and dump the ants and dirt into the ant farm. Several ants will likely escape. As soon as you have the ants in, pop on the lid.
In the picture I tried to dump the ants directly from their hill into the ant farm. As you can see, chunks of dirt got stuck and lots of ants escaped. The baggie method works much better.
Step 5: Hang Up Your Art
Leave your ant farm outside for an hour or two out of the sun to make sure that the ants aren't escaping. Then, hang it on a nail. If you are brave, you can hang it up in your house, but I keep mine in the garage. Once I had a store-bought ant farm with a tiny hole at the bottom, and the ants tunneled directly to it and escaped. That's why I'm wary about having it in the house.
Put an eyedropper and a flashlight by your ant farm to make care easy. You can feed your ants tiny crumbs of anything you would eat--Cheerios, strawberry, bread. Don't put anything too big in though, as it can get moldy rather quickly. Keep the dirt slightly moist but not too wet.
Ants are very fun to watch. They are such hard workers from the moment they're dumped into their new home.