I've only seen baby weasels in real life once. And they were having an absolute ball. They were dashing about, play fighting, leaping in the air ... a bit like this fella.
Walking through a forest many years ago, a mother weasel and four tiny babies ran across the path right in front of us. They were gone in seconds. The only other experience was when then cat sadly killed one that had ventured into my bedroom cupboard when I lived in the country. Apart from being sad, the lingering smell was dreadful for weeks, they are members of the skunk family!
And his 'mouse' antics are preferable to having a 12lb iguana standing on your keyboard, typing random gibberish while you're posting on a forum .............. which is exactly what used to happen to me.
Or having ol' chubby sleeping on the router and having it shut down because it over heated. The cry used to go up "that effing cat is on the router again" lol.