Here is a picture of a more recent FHM condo I built with the flotation device to keep them from sinking when they get waterlogged. I did not take any pictures of these while building, but they are similar to the ones in the thread linked above. Notice also put some rocks on top because initially the wood is buoyant and tends to float too high in the water.
I make these out of whatever scraps I have laying around. The wood is pallets and crates that have had various parts delivered to the farm at some point. The foam insulation is some from old turkey barns we tore down. The only thing new is screws that I screw the parts together.
One thing I noticed on the original ones I built. The top was very open and green herons would perch on top and pick off the FHM that spawned on the upper level in very shallow water. Later condo's I built with a more solid top or at least less open area to give the FHN better protection from bird predation.
Pictures below of the last two I built for the new sediment pond that will act as a forage pond for a while (till LMB swim up the overflow tube during an unusually large rain event). Last picture shows a regular pallet that I put in a month or so ago. It floated when put in, but has since sank as shown. Thus the idea of adding flotation so the FHM condo's will not sink to the bottom.
Will remove these from the pond about November and put them back in about next April.
