I have ANTS AGAIN!!!3,rd time!

I found out where they came from....my window & I sprayed ant killer all around the tank & inside & outside of the window.I took my hermies out before I did all this & put them in iso.I washed out there food bowl,shells,& a few toys.Anybody know how to prevent the ants from coming back?I'm getting really really frustrated right now.Idk what to do???