1. Good image, well exposed. Ideally you want to capture animals more in a 3/4 forward profile (so that they are looking toward you, not away from you), but you also have to take what you can get.
2. Slightly (~1/3 stop) over-exposed, but that's minor. Critical to good animal photography is the sharpenss of their eyes. In this case, I think the point of focus was more on the chipmunk's haunch rather than it's head. Also try and avoid cropping so that you lose little bits; in this case the very tip of the tail.
3. A rather bland image with no discernable main subject. In cases like this, circular polarizing filters and/or graduated neutral-desnit filters can really enhance skies and improve the contrast between clouds and sky.
4. Very nice, good and sharp, needs a much tighter crop to focus the eye on the main subject however.
5. Another nice close up.
Overall, some very nice work there. A couple of general comments. Try and avoid centering your subjects. As a general rule, the "Rule of Thirds" makes for a more pleasing image, that is, off-setting the main subject from the middle of the image by 1/3. In the case of macro and close-up work, this doesn't always hold true; what's important for those types of capture is to make sure your subject doesn't get lost as it does in the case of the grass-hopper. Don't be afraid to crop aggessively - there's nothing wrong with having the subject take up more of the frame.
Heya d-ran, and welcome to ThePhotoForum.
As you can see, I went into your post and edited it some: I put spaces between each photo so they no longer run one into the other, and I numbered them. Makes commenting easier.
And had not tirediron been here before me, I would have said the very same that he said, but ever so often he beats me to it, and when tirediron has been around, there is little more to say...