I have a question!

I Own a small Messor Barberous (black Harvester ant) colony, but I don't exactly know how to give them water properly. I have seen them start to borrow in the sand of the out world, I think this is bad because there meant to stay in the nest. The nest itself has two large sponges on either side, if you water them the water takes along time to sink in through the hole that you squirt water through.

I'm wondering if the dampness in the nest will help the ants in their thirst? I don't know, please help.:(