I collected the Honey hidden in the empty space in the grass on the left side, and the Dowsing Machine reacted again when I came back later. This is a big find for all of you that are looking for hordes.
Whilst that is nice, Sweet Scent is by far the easier method. Not only that, Combee is your best friend for Hordes: naturally has Sweet Scent when caught and has Honey Gather as the default ability. It is literally the only time a male Combee is useful (since females can evolve if you leave EXP Share on...).
If life gives you lemons, sell 'em to Tom Nook. Black 2 FC: 0132-9980-0476, 3DS FC: 5284-2520-2972 (Pokemon IGN: Aki)