I have a Tetramorium immigrans colony that seems to be very shy and slow in growth in general. This is I think their third year and they have around 75 - 150 workers if I had to guesstimate. They are very, very shy with foraging, and they rarely head into the outworld. I sometimes get so worried that they aren't eating that I pop open the nest for a moment to put in some food (which they gladly eat).
It's also weird that they are literally scared of some peanut butter I offered them. Like I have seen 3 different workers "sneak up" to the peanut butter, touch it, and then run off like they were dared to poke it. The most I've seen this year is 2 in the outworld at once, and only one was eating some breading for a taquito that I gave them, since my mom who is also keeping a colony of Tetramorium i. said that hers like the breading. I live in Vermont btw, if that helps with any information about how my ants are supposed to behave seasonally.
Is there anything I can do to make sure they are getting the food that they need? I give them water, and my room (and by extension their nest) stays around 70-75F consistently, except in winter when it goes down to usually 60-65F and they sit next to a wall where it is usually a bit colder. I have no idea what they are missing or don't like.