My greyhounds love to poke. They have those long needle noses for a reason. Once when hubby and I were lingering overlong at the dinner table, and Capri had been whining at us to get a move on for some time, she got tired of being ignored and ran around the table and rammed her nose into his side just under his arm. That got quite the reaction.
Another time, our big boy was feeling excited that I had just come home, so he ran into the room, reared up on hind legs and without touching me anywhere else, poked his wet nose into my left eye and then ran away. He was so fast that he did it before I blinked. Yeah, dog snot in your eye is something special.
Before I had these guys I was skeptical why people would use targeting (teaching the dog to touch specific things with their noses) as the beginning point for many tricks. Now I see the folly of my former thinking. Dogs just naturally use their noses to touch things. Mine can’t look at anything without also touching it with their nose. It’s not just smelling it, it’s definitely a touch. Makes me think the nose is wet because it’s kind of like a tongue, with nose-tastebuds on it or something.
Dolphins love to poke too. It certainly has nothing to do with sense of smell, as dolphins don’t actually have any nostrils at the end of their snouts. Dolphins are said to have a poor-to-nonexistent sense of smell anyway (although I don’t know of actual research on that).
Target training is used in training many kinds of animals, including dolphins and sea lions. First of all, by teaching a critter to touch a target, you gain a great degree of control over the animal. At first, the target may be stationary, affixed to a wall or fence of the animal’s enclosure. Then, you put the target at the end of a long pole. Then the trainer can stand outside the enclosure and use the pole, with the target at the end, to guide the animal around. A well-target-trained animal will keep its nose on the target even as the trainer moves it around.
ETA: Tutorial on target training by Karen Pryor. She talks about doing it with dogs. In fact, she was also one of the principal founders of Sea Life Park in Honolulu, and has written a book about her adventures in dolphin training called Lads Before The Wind.
My ex-cat, the late, great Justin, would walk into a room full of people and stare intently at a spot on the ceiling. After a while, people would wonder, “What is he looking at?” and stare at the ceiling too. Once he got everyone in the room looking at the ceiling like a bunch of fools, he would look back down and nonchalantly walk away.