I wanted to create a better/cheaper option for starting harvester ant colonies for the upcoming season.
Buying mini hearths for all my potential future colonies isn't the best option so I wanted to experiment with different options.
Here I mixed some non sanded grout, added in a little fine sand. I have 20mm test tubes. I poured in a little. it was thick as it went in so I advanced the grout a bit more with a bamboo skewer and spread it around the test tube. I left ~1 inch in the back uncovered. Then I poured in fine white sand and gently tilted it around until the grout was covered.
Hopefully this can produce better results for starting ants like pogonomyrmex.