Friday, April 6, 2012

Ants (how to build a formicarium)

Approximately one year ago I got Carina an ant farm (see full details here: Over the year I took it over from her and now I am the main ant keeper in the house. Unfortunately the first colony did not fare well and currently only the queen and a sole worker are left. We have think the queen is unfertilized and thus none of her eggs develops*. Luckily we, by chance, collected 8 queens form the wild at the end of July 2011. We sent a few to another ant keeper in the hope that he will send back a different species... At least he identified the species as Lasius niger, also know as the black garden ant (same species as the unfertilized queen). All but one of the remaining queens we had died BUT the survivor produced eggs and just before the end of the year we had a small colony. During winter this species hibernates and we saw renewed activity about a month ago. At this stage the temporary nest was made from a small jar inside a larger jar with sand inbetween them. I was thinking of getting ytong** to carve into a new nest but a nicer material presented itself.

During our recent trip to South Africa (, we had a short holiday in the Free State, close to the Golden Gate Highlands National Park.

The area is known for its lovely sandstone rock formations and I was lucky enough to find some discarded pieces from a sandstone mine (the picture above is a prominent landmark in the park known as "Brandwag" but the stones were collected from a stone processing factory outside the park on a private farm with mining rights).

I got three stones that were approximately 35x50x250mm and completely flat on 3 sides. One of these broke during the flight back and one during carving.

The other stone is a broken sandstone tile, approximately 300x200mm and completely flat on one side. This will be carved into a formicarium in the future.

There are a number of very nice tutorials on how to construct ytong nests, see for example: The following is a short description of how I did it (but the main approach is similar to making a ytong nest):

I used a Dremel to carve the nests. First I carved the rough outline with a 3.2mm cut-off wheel. I used 2 wheels for this one nest and at the end they were worn away to such an extend that I could use them to carve some of the details. I also used a genetic 4.4mm diamond-tip-wheel bit to do most of the detailed carving and hollowing.

During this process I also drilled the holes to attach the tubes, a hole at the top for hydrating the nest and one at the bottom to attach the nest to the base.

All three flat sides were carved into nest areas. At this point it should be noted that sandstone is deceptively strong. The carving took some time and effort but was manageable. However, drilling is quite difficult and required much more effort than I expected. I recently got some ytong and this material is much much softer than sandstone. I am looking forward to having more sandstone nests but are not looking forward to carving it. Also note that sandstone cannot be sawn using a normal saw and I used sandpaper and quite a bit of manual arm labour to flatten the bottom side.

After all three sides were carved I glued the top and bottom together. This is the part that broke early on during carving. I used superglue (cyanoacrylate) mixed with dust obtained from carving. I am reasonably sure that the glue, when dry, poses no risk to the ants. The straw at the top is to ensure that drilled water-hole remains open through both parts. 

I bought a 50x50cm pane of glass from which I could cut strips that fit exactly over the nest areas. 

The glass was fixed to the stone by aquarium silicone. The edges were sealed only after all three glass strips were fixed to the stone. At this point I also used silicone to fix the connection tubes to the stone and seal the holes around them.

I used a piece of pine to carve a sloping base. Into the base I carved a hollow for the stone to fit exactly. The base was attached to the stone by a screw that went into a hole in the stone that was filled with silicone. I aslo placed a bit of silicone in the hollow to ensure that the whole thing stick together and to not wobble.

The final product and the outworld:

I stained the pine afterwards (see the next picture) and once this was dry I connected the old nest to the new nest. I waited one week for the whole nest to dry and all the silicone fumes to evaporate (also used a bicycle pump each night for a few minutes to help the process).

I removed the small jar and the queen started to wander around. I placed her in the new nest and all the workers in the outworld. They quickly found their way to her and soon brought all the eggs and larvae to the new nest:

Some issues, tips and future plans.
During the build there were a number of things that I noted for future reference.

- Sandstone is quite hard. Much harder than ytong and not the easiest material to carve.

- Cutting glass was much simpler than expected.

- It is important that the connection tubes fit quite deep and tightly in to the stone. Although silicone is used to seal the holes around it, it is not ideal for keeping it stuck to the stone. Both connection tubes in the current nest have a bit of play and this means that extra caution is required when attaching/removing tubed not to pull them free from the stone.

- The hole in the top is used to hydrate the nest. However it is necessary to add water every day to keep the nest moist. It was also only possible to drill the hole deeper than will be possible normally since the stone was broken. A possible solution for this nest (to keep it hydrated when going on holiday) is to place a wet cloth over it with its end in water. Wider holes in future nest could may work but could also result in breaking the stones (any other suggestions will be appreciated).

- More water seeps through the break-line than through the rest of the stone. Luckily is not a problem but might have been if the break was lower down.

- I need to have more patience when dealing with ants that are known to be sessile!!

- I plan to carve the other stones, as the colony grows, and set up the formicaruim as indicated below:

However, before I start on the next tower I am going to try to make a ytong nest and try to grow a Myrmica rubra colony (I will soon order a queen from the antstore).

I hope the the Lasius colony is happy in this nest and continue to grow (currently at approximately 20 workers) throughout the year.



*Ants mate once per lifetime during the mating flight, usually on the wing. She can thus not be mated at this stage, as a number of people have suggested. He fate is unfortunately a sad one and she will probably not see the end of this year.

**ytong is made a lightweight cement based building material. It is porous, very light and ideal for constructing formicaria:

1 comment:

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