The Ants No More Bait Stations are designed to prevent non target insects like honey bees from getting into the station. Ants enter the station through the small holes in the center stake and this hole is not much bigger than a large carpenter ant so small enough that a bee would not fit. You would push the station into the ground to the first hole, or you could go a little futher for less entry points.
If you already have ants coming into your home you will want to put some stations near the current activity for the ants to quickly find the bait. Putting stations near your home will not necessarily draw more ants to the house from the yard, but spacing the stations out across your property can be beneficial to get ant mounds in other areas of the yard you may not see. There is not a set placement you have to follow to get control over the ant populations in your yard with these stations.
Yes, the holes on the Ants No More Bait Station are big enough for all ant species to get into.
Ants No More Bait Station help keep the elements from the products applied inside. It is possible that in certain situations that moisture/condensation can occur. We would recommend applying fresh bait if this occurs.