I'll try that, thanks! I noticed that he's perfectly calm all day and this only happens at night once it gets dark. It's a little hard to distract him once he's set on attacking a pillow/humping, but a treat might work.

I've been dog sitting in the owner's home for five days now, and every day, all is good initially, but at the 3.5 hour mark of being home, awake, and interacting with him, he starts to freak out - panting heavily, attacking pillows, climbing on me to hump my leg. The first day, the owner said that this is his way of getting used to me, but is that still the case after 5 days?? I've always interacted well with dogs and have stayed very close to the owner's schedule with him, making sure he has plenty of food and water throughout the day. Has anyone experienced this or have any tips?