The adult muskrat is generally a solitary creature, except when breeding. I have only seen one or two a year, but always the muskrat seen was on its own. That changed yesterday when I watched three of them sitting on a log together eating aquatic weed. Indeed other observers have seen four of them at this same spot. They are undoubtedly youngsters that were born just last year.
Two muskrat kiddies were sitting on a log eating aquatic weed that they would fetch by individually diving into the water. Each would then return to the log to eat the weed.

Such good looks at their web feet…interesting, Alistair…thanks!!