What is this?

We do not have ants in the pants, but on the other hand they are swarming on the balcony. Several hours have been spent emptying the balcony of everything, except the clematis, which we can not take away because it clings to the trellis. Then everything has been scrubbed several times with soap and vinegar. Vinegar has been sprayed into all cracks. But still we see ants. Now it is war and I am taking to the gross artillery with poison!

So during all the work I saw an excellent object for a riddle.
So, what is this?