The way I see it, after a certain age memory lane extends backwards in and out of the sun, around and under the trees, occasionally flirts with littoral boundaries ... in other words, there was a lot going on there. When you continue walking along memory lane you can see the end just ahead littered with garbage cans and medical refuse. The clouds are low and dark as if a storm was brewing and you are thinking I'm not sure I should any farther down this lane but your feet just keep going as if propelled by some unseen force. Sort of like if you were driving a modern car with online connectivity that suddenly gets hacked and hijacked and you are no longer in control of the wheel, the brakes, the accelerator, the radio (
what, a radio, how did that get here). The door are locked too! OMG, I can't remember what I was texting about. Couldn't have been important.
You are quite right Joanne, a beaver's tail is unique and a muskrats tail is ... well, it rat-like. The thing is, if they are swimming can you really see the tail. It's been my experience that beyond the shear size difference ( beaver weighs ten times as much as a muskrat) there are a few other differences that might be visible when these rodents are seen swimming.
The beaver swims with nothing much below its head visible above water level. The nuchal area (back of the head) and cervical part of the back is generally all you will see, the rest of the beaver and its tail are submerged. A much lighter-weight muskrat swims with a substantial amount of its back visible above the water. Even that rat-like tail may appear all snake-like from side to side. Also, if a muskrat is swimming in a pond and it sees you standing on the bank with your hands on your hips like aunt Clara, or uncle Fester it will steer away from you and rethink its route of navigation. A beaver, on the other hand, will not alter its course. It will quite likely ignore you and perhaps give you a submerged finger.
Swimming muskrat with back and tail visible
Swimming muskrat with rump visible
Muskrat with good portion of back visible
Beaver with head and neck above water
Muskrat with notable white snout
Beaver with bullish head and no real off-white snout