Right this one took a while but was a stupid mistake in the end. At some point I forgot to connect the colony ID for the enemy being attacked into the array and instead added the default of 0. This leads to there always being a possibility of colony 0 being attacked regardless of there state or even existence in the game. This will have also messed up the revenge mechanic (enemies are more likely to attack someone who has attacked them) so this has been fixed also.
Now for the other thing you pointed out about wood ants!