Hi I do have some small brown ants that have just moved in. To keep them at bay I use Windex a very small spray when I see one. BUT on the side of my toilet bowl they have built something? It looks like sand about 3″x3″ patch twice i have removed the patch; and each time they make the same patch. This time I have let them build; it has been two days of building; and the patch is growing. Kindly inform me what is it that is growing? I would love to know before I destroy it. Thank you for your help.