Ack! 2nd place in the group with 4922.
Now I have to go back to my neglected life.
[QUOTE=Frylock]
I think their damage is reduced by a certain amount automatically, so that they are only damaged by upgraded towers. You can one-shot them with a fully upgraded version of the cheapest tower.
[/QUOTE]
OOOOOOOooooooooh.
Geez, I had just finished laying out the whole field full of guns, and I hadn’t upgraded them yet. So I was all, 
WTF? Some of mine were the bigger, more damaging kind, but were just not upgraded yet.