Gauge is not at all critical for this project.

Using multiple strands of scrap yarn held together is highly recommended. I typically use between 6 to 9 strands of whatever yarns I have on hand, combining them until the yarn is the equivalent of a super bulky weight yarn (anything from 2 to 4 WPI). Making these beds consumes stash like crazy since each bed weighs about 1.25 pounds (567 grams) when complete.

Personally I am not at all concerned about using felt-able fibers; made with regular wool, the beds will felt. If you mix natural fibers with synthetic, the project may partially felt but I rather like that and the animals certainly don’t mind. If you use non-felting fibers the beds won’t felt. The animals don’t mind that either. All work and seeing what happens is part of the fun.