MB is right, treat the ant problem for the entire apiary, the borax works well or use the ant baits that come in the tin or plastic containers, the holes are too small for the beees to enter and placing a few in the travel paths of the ants will knock them down quickly.
Once the ant problem is under control then work at establishing your TBH using a following board. TBH's have too much vacant space, at the start, for the bees to control the space well. In a Lang the quantified space plus the frames and foundation, give the bees much more control over the interior space and the entrance. TBH's lack everything but space so limiting the work space is muy importante. Give the bees enough space to house the cluster plus an inch or so, depending on bar width, on each end, then as the bees build comb and population expand the space a bar at a time by hop-scotching the rear-most drawn frame.
Bees will only draw comb underfoot, so if they don't have the population to expand onto the next frame they won't do it. Also they will leave drawn comb but not brood combs. In a Lang the outer 2 frames are almost always storage combs, in a TBh it should be the 1st and last frames. This is an important factor to consider when manipulating frames within a hive.