I am responding to an email which I accidentally deleted in which the writer was concerned about how to tell different animals one from another. 
SHE mentioned a squirrel and a chipmonk. 
This whole business of animal confirmation is a real pet-peeve with me, because so many are so very alike structurally, or so it seems. 
Please! If anyone can prove me wrong, please give me the evidence. 
This comes from one who has spent a lifetime learning how to tell one dog breed from another. When you rule out size and color, many are confirmationally so similar, it would be hard to sculpt or draw one and know it was not another. A dog breeder, and certainly a show judge can tell the difference between a Scotty's head and that of a West Highland White Terrier, but most people would say, "Well, one is white." 
The fact is that there are clear differences, but only a breed enthusiast would notice. 
The same goes for woodland animals. 
The fact is, structurally, a squirrel and a chipmunk aren't all that different from one another. The chipmunk have bigger cheeks, but if you are work ing in a one to four or one to six inch  scale, the difference isn't that easy to discern or to sculpt or draw.   
It's all about color and position. 
Squirrels are normally posed sitting on their haunches with their bushy tails sticking up along their backs with the tip curled outward at the end. Their front paws are extended just below their heads, and they are usually holding an acorn. They are either gray or rusty red. 
I haven't seen that many figurines of chipmunks, but from what I have been able to learn, they are very similar, except for color. Except for the ringed tail, I haven't the foggiest notion of how to distinguish a raccoon from either of the above, except again, for color.  
Since I began needle felting, I have spent a lot of time listening to tutorials on some of the animals mentioned here. Their head and body shapes are very similar. 
Makes me think those beany babies weren't all that far off. 
The bodies are, basically, a cylinder. The heads are cones with slightly longer or shorter muzzles. You can also make them by making a ball for the head and a cylinder, slightly larger at one end for the muzzle. Cat heads are confusing no matter what instructions you read.  
(Never snout. "Oink, oink, snort, snort." Dogs, cats, and civilized animals have muzzles.) 
Mice have big round ears. Foxes have short pointy ears. Otters have small rounded ears, as I believe farrots, badgers, and ermons. 
I don't know how to distinguish a hamster from a mouse, but I sure bet those who own hamsters can tell you and will jump all over me on that. 
From the descriptions I have read, there won't be much in these coloring books about different woodland animals. 
 Farm one animals are a little more distinct from "another. A cow, a sheep, and the pig are quite distinct. When it comes to llamas and alpacas, I haven't a hope of telling one from another. 
There are YouTube tutorials on how to felt a sheep and a highland cow which makes them sound very similar to one another. Now I know that a highland cow is a little different from a milk cow. They are shaggier, for one thing, but there must be other differences. From the tutorials, though, you can't really tell. 
I mentioned one to four or one to six  scale. That is a workable measurement for small figurines. If you are making a drawing of a chipmunk who takes up most of an eight and a half by eleven page, you will really need to know more about confirmation than I have said here, but if you are drawing a squirrel sitting on a tree branch as part of a larger scene, you will probably keep very close to the one four or one six  proportions.
Some books on bookshare which might be helpful include, Little Needle Felted animals, and Wool pets. Not Little felted animals. That book concentrates on color, rather than detailed confirmation. There is also Wool Buddies, but those are really oversimplified. 
If anyone out there can give us better descriptions of woodland animals, I would certainly like to here from them, and, I suspect, others here would too.