this game is so difficult but so cool...
Alright, so you want to have a good economy to sustain your ants, so try to make about 2-3 worker ants at the start, then start building a couple warrior ants (5-6) to defeat the red ant guards defending most food piles. Don't make too many warrior ants since they will eventually eat all food and then your queen dies. It is okay to send ants into their death to keep the upkeep low. Finally the game is designed in such a way that you can choose between various strategies (mass workers with upgrades, mass scouts with the range upgrade or some workers/warriors or a mix). Mass workers goes a long way but is eventually really difficult to pull off versus the beetle with splash damage. Mass warriors will lead to a queen death eventually unless you keep raiding food piles a lot. Mass scouts is really good but you need to get to a critical mass which requires some micromanagement.
In order to beat the waves you need to study the enemies closely, each enemy has a specific way of defeating it (I won't spoil how the enemies work, you have to find this out yourself ;)