Mike , I like Terro also, it works very well with ants inside the house.
Callie, Welcome to the forum..
I'm using ant spike right now for my 'chids in the yard, which have hordes of black ants living in their pots. I should take a pic or two next time I water, the ants would come up with eggs in their jaws , running for their lives. It's disturbing, what's worse is that the ants ignore the poison spikes altogether, so I spent $8 for nothing. Soaking doesn't work, since they would just climb up on the leaves to get away from flood and be back down into the medium later ( don't lsoak the leaves, you could end up with the rot, which is much worse. But I guess you can wipe them off, having only one orchid... I'll keep looking for better solution for us.