I was using food treats (doggie sausage cut into roughly 1/4" cubes) in the yard while practicing some agility moves with Tika. One piece popped out of my hand and landed among the wood-chip mulch in front of the U-shaped tunnel. The ends of the tunnel are about 8 feet apart and the food dropped probably about 4 feet in front of and roughly between the two ends. I couldn't find it and Tika didn't notice that I dropped it, so I ignored it.
I got Jake out a bit later. Got him riled up with his toy and sent him charging into the tunnel. He blasted in, charged out, skidded to a halt about 6 feet beyond the end of the tunnel, made a 180-degree turn led by his nose, bee-lined to within about 4 inches of where the food had dropped, zeroed in on it quickly, scarfed it down, then turned and zoomed on in his original direction as if nothing had happened.
Wish my nose was that good!