if i give mine rubra honey they dont eat it but if i give them a spider its gone in 5minutes.they like the hard food not the liquid food in the winter(fridge).
I give them 1 time a week a very small insect, sometimes they eat it other times they leaf it. Also i put in a small cup with honey and refresh it 1 time a month ore something. (in hibernation)
Its a VERY VERY new colony i got off miszt... still in test tube over winter.
so if i'm not mistaken you now have a small colony of Lasius niger who are in hibernation at this moment and still are in the tube ?
How big is small ? 10 workers ?
If the colony is that small they probably would not eat much/nothing during the hibernation. You could put in a little honey. Insects is not needed if they are in hibernation.
counted around 20 workers.. and yup still in tube.
okay, well just give them a little honey than (refresh it once a week) and water. If they have that they will survive the hibernation. (must say, some ants die during hibernation, not always the keepers fault, but if you stick with this they probably do just fine)
Give them fresh insects when they wake up.