I mentioned before how DG is cold a lot. We keep the thermostat at 68 degrees in the winter because its expensive to go higher. In the summer, I rarely put it above 72 (and most times, its at 70). That's because anything warmer, I swell up and have my own health issues. See, you can always put on a hoodie, you can't always get naked. Plus, you can always add another layer, you can only get naked and that's it- you can't get MORE naked if you're still warm.
But back to the dog aliens.
We have those Chihuahuas. And Chis by nature, are cold. Ours absolutely hate wearing sweaters. When we put a sweater on Luna, she runs around the house in a frenzy, rolling on the floor and in the dog bed and on blankets till she wriggles out of her sweater. Jasper does the same, but I'm not sure how because he's very stealthy about it. He's got the sweater on... disappears... returns without the sweater. When we put one on Bruno, he walks sideways and falls over like we've drugged him. But all three will climb inside your shirt if you let them.
Whenever DG is wearing a zippered hoodie or even a blanket, at least one Chi will climb inside. And when that dog wakes up and climbs out, the result is always the same.
DG screams and wails, "Its an alien! AAAALLLEEEEE-AAAANNNNN!" and he "dies" in his chair till the "alien" gets bored with it all and jumps down to venture forth on Earth.
Sometimes, if nobody is in the room to enjoy the above spectacle, he'll declare loudly, "I've given birth!" and then he baby talks whichever dog spilled forth from his sweatshirt.
Here is photographic evidence of the "alien invasion".