Got home from work Tuesday, to find the kitchen sink backed up. Emptied the cabinet, pulled apart the trap, and found nothing. Next, I go to the cleanout in the line, downstairs, right below the sink. Pull the cap, and of course fill half a drywall bucket. Take a peak . Nothing, atleast up to the corner elbow. From the elbow is a 20′ straight run, to the next elbow. Yeah, it should be a Y with a clean out.Decide to cut the low end of the 20′ run, figuring the blockage is in the straight run. Cut the pipe, which I know is full of water, and nothing comes out. So blockage is in that long run. Cut the other end, near the first corner, and Gushhhhhhh. Took the whole pipe outside, to flush with the hose. It instantly fills. So, I stand it up on end and tap it on the frozen ground, and Whumpppp, out comes the blockage. Inspecting this pile of crud, I find the culprit! A red squirrel had crawled down the vent stack, and got stuck. Suppose seeing he’s a red squirrel, he thinks he’s Santa or some thing.Funny thing is, this exact thing happened once before, same pipe, same spot. Guess, I’ve got to put a screen on that vent stack. Never seen one , and hope it does’nt cause an ice block in the vent. Anyone ever heard of such a thing happening? Or do I live in the land of Kamakzie squirrels?