The Formica fusca ants really suck. What the Fusca need is a boost. It is a known fact that they have formic acid, this could be implemented fin game modes such as Freeplay and, Multiplayer in the far future. Another fact is that they sometimes have multiple queens within the same colony. Perhaps there could be a chance for multiple queens that spawn underground. Another multiple queens idea is that if there are more than one colony of Formica fusca, they could "work together" by sharing food supplies, or combining forces to take on a massive enemy, like the infamous Rufa.
Ants are beautiful,
but if fooled around with,
can be deadly.

Personally, I think they're perfectly fine as a a more simplistic colony type.  I've mentioned this before, but in multiplayer I think it would be much easier to scale the underground based on your colony choice.  Thus, the Formica Fusca could just get a much stronger start than far more powerful colonies, while the strongest colonies would be forced into difficult situations in their nests. 
And on the sixth day, God created ant in his own image, and gave them dominion over the earth and all of its creatures.  Amen.

I agree, I feel they are meant to be a simple species for the player to learn the game's basics. Basically nothing is known about multiplayer. We don't even know whether it will be different species against each other in multiplayer, it could just be formica ereptor vs formica ereptor.

I'm hoping the player does get to choose their species in multiplayer, though.
Honestly I think it would be pretty cool if some species would have advantages over others in certain maps. I think it's pretty safe to say leaf cutter ants, for example, will be much stronger than Formica fusca. But if there would be a map that is bountiful with aphids that leaf cutter ants can't harvest, and very few leaves, the power of the leaf cutter ants could be balanced out with the fact that they have much less food than Formica fusca.

I'm hoping there will be some maps that favor certain species due to the environment, like leaf cutter ants should have a clear advantage over wood ants in a rainforest, and the opposite on the beach. I also think having some maps that are as close to perfectly balanced as possible are also a good idea to have. This will allow players to adapt in some situations, but also go head-to-head without having to worry about disadvantages in other situations.
Posted from my Zombie bunker in northeast Ohio.