Could you please not pre-zoom your pixel art? Pre-zooming makes it hard to see your art at different sizes and to make edits.
The design is cute, but it's a bit hard to read as a rat because the nose looks like it's one entity with the "collar", so the character has a round silhouette, not very rat-like. Have the noise a couple of pixel above the collar,or move the whole head forward a bit so that the nose can protrude and give the character a more rat-like silhouette.
There's some very intense rotation happening in the hips, which isn't bad, but the rotation isn't continued at all into the upper torso, making it look like the character swivels at the waist.
Since the character is always facing slightly towards us, that means they'd have to rotate a lot more for us to see their butt, so the swiveling is very intense. It's fine if you want to exaggerate the movement so much, but make sure you do it for the other side, too, that is, we should be able to see more of the front of the character when the other leg is forward. That might be too much movement though, so it might be better to tone the butt rotation down instead.
I like the idea of basing enemies on real animals, however, they look out of place with the main character because they're so realistic. There's also a scale problem, most of these insects are much smaller than a rat. If you stylise them the way that you stylised the rat, that would make the realism and scale issues go away.