I have a 3 year old Formica colony I have been struggling with.
In the first year the queen had about 20 plus workers. after diapause I allowed them to move into a small founding formicarium with outworld area in one setup. The queen didn't lay any new brood after diapause. I continued to offer sugar and small amounts of protein sources. The colony lost a few ants one at time slowly over the course of the summer. I noticed when I would occasionally add a wet cotton ball to the foraging area the whole colony including the queen would come and sit on the cotton. I figured either they werent getting enough water or the nest wasnt humid enough. So I increased the nest water amount and started offering them water regularly.
Having no new workers and losing some over the course of the year they went into diapause with maybe 15 workers. When I brought them out of diapause they had lot a couple more workers and over the first month out lost a couple more. I got advice on the discord to move the queen and 6 remaining workers back into a test tube. Shortly after that the queen began laying again and by May was back up to 25 workers. The colony has been doing good and is now in a 2 test tube with attached small foraging area setup. They have 2 fresh tubes with access to water and a sugar source and they take protein regularly.
However this month workers started dying again about one a week. Normally I wouldn't be concerned at this but again the entire colony is starting to move into the outworld and huddling around any water source. I changed the test tubes for fresh ones and made them wetter to increase humidity. The test tubes are also semi sealed with cotton and a straw.
I let the water source in the foraging area dry up and noticed that the colony still found a place to hangout in the outworld instead of the test tube. It has been super hot here and I thought maybe the test tube was to hot inside. So watched to see if they went back into the tube in the evening when it cooled down and they did. If it is the heat I could try moving them into my wine fridge on the highest setting it might bring them down 10 degrees.
Thoughts? Is it a humidity, water, or temp issue? What are some things I can try to rule out possibilities. Could there just be something else wrong with the colony?
Thanks for any tips