Ants don`t eat too much, don`t worry, you could afford the food.
Someone here in the forums had a massive Solenopsis geminata colony that ate an entire large can of dog food PER DAY. And grasscutter ants are so efficient at what they do that they compete with CATTLE.
An average adult wood ant colony (1 millions workers) drinks about 200 liters of sugars per year and over the same time eats close to 30kg of insects - which doubles if you ignore hibernation.
However your colony most certainly runs very inefficiently at the moment because it is highly unlikely that the workers are capable of properly supplying the queens with enough food. That means the huge population explosion is still a good way ahead.
Edited by Serafine, May 18 2017 - 10:41 PM.