The second task is only a little bit harder. It is important to increase the difficulty slowly, and only when the previous task is executed perfectly. Furthermore, during the week, we each task is repeated multiple time to reinforce the learning process. As you can see, Nelson hesitates to lay down (which is our desired sign when he finds the scent), but I waited until he realized he will not get the treat by staring at me. Dogs always try to find some loophole to get the treats faster, so we need to be very consistent.
During the third task I had to make Nelson wait in the other room, so he couldn't see where I put the scent. He realized he can sight too, not just the nose.
Text divider is courtesy of KittyGirl, posted in The Terminal's discord.