Jumping in with your organic forms with contour curves, you're doing a great job of sticking to the characteristics of simple sausages. One thing to keep in mind though is that the contour curves should be getting wider in their degree as we move farther away from the viewer, as discussed back in the Lesson 1 ellipses video.

Continuing onto your insect constructions, overall you're doing quite well, with a lot of focus on building up from simple to complex, and a fair bit of respect for the solidity of the forms you're laying down. This respect for the 3D nature of your forms is upheld through the majority of your constructions, although in a couple it gets a little lax - mainly the ant and the rhinoceros beetle, so I wanted to use them as an opportunity to talk more in depth about the distinction between the choices we can make that occur in 2D space (where we're just drawing lines on a flat page, and that's how we think about each new mark we add), and actions we take in 3D space where we're actively thinking about every new form as though it is being attached to an equally three dimensional structure, and even reinforcing the illusion that it's all 3D.

Just to be clear though, you do a pretty good job throughout much of your work.

So! Because we're drawing on a flat piece of paper, we have a lot of freedom to make whatever marks we choose - it just so happens that the majority of those marks will contradict the illusion you're trying to create and remind the viewer that they're just looking at a series of lines on a flat piece of paper. In order to avoid this and stick only to the marks that reinforce the illusion we're creating, we can force ourselves to adhere to certain rules as we build up our constructions. Rules that respect the solidity of our construction.

For example - once you've put a form down on the page, do not attempt to alter its silhouette. Its silhouette is just a shape on the page which represents the form we're drawing, but its connection to that form is entirely based on its current shape. If you change that shape, you won't alter the form it represents - you'll just break the connection, leaving yourself with a flat shape. We can see this most easily in this example of what happens when we cut back into the silhouette of a form.

So for example, there are definitely a number of examples of this on your ant construction. In red I've marked out where you've cut into some of your silhouettes, and in blue where you've extended off them. When it comes to ellipses, this obviously wasn't intentional - but as noted on your work, always use the outermost perimeter as the silhouette's edge. And on the legs, you were just following how I approached the wasp demo - but I will share a better way of approaching it further down in this critique.

Instead, whenever we want to build upon our construction or change something, we can do so by introducing new 3D forms to the structure - forms with their own fully self-enclosed silhouettes - and by establishing how those forms either connect or relate to what's already present in our 3D scene. We can do this either by defining the intersection between them with contour lines (like in lesson 2's form intersections exercise), or by wrapping the silhouette of the new form around the existing structure as shown here.

This is all part of accepting that everything we draw is 3D, and therefore needs to be treated as such in order for the viewer to believe in that lie.

You can see this in practice in this beetle horn demo, as well as in this ant head demo. You can also see some good examples of this in the lobster and shrimp demos on the informal demos page. As I've been pushing this concept more recently, it hasn't been fully integrated into the lesson material yet (it will be when the overhaul reaches Lesson 4). Until then, those submitting for official critiques basically get a preview of what is to come.

Now, I can definitely see that you're making considerable effort to stick to the sausage method when constructing your insects' legs, but you aren't always following it as consistently as you could, in terms of adhering to every point raised in the sausage method diagram. Most notably, while you stick fairly closely to the characteristics of simple sausages, you do frequently forget to define the joint between them with a contour line.

The key to keep in mind here is that the sausage method is not about capturing the legs precisely as they are - it is about laying in a base structure or armature that captures both the solidity and the gestural flow of a limb in equal measure, where the majority of other techniques lean too far to one side, either looking solid and stiff or gestural but flat. Once in place, we can then build on top of this base structure with more additional forms as shown here, here, in this ant leg, and even here in the context of a dog's leg (because this technique is still to be used throughout the next lesson as well). Just make sure you start out with the sausages, precisely as the steps are laid out in that diagram.

All that said, overall you are certainly progressing well, and I'm pleased with your results. What I've raised here can continue to be addressed into the next lesson, so I'll go ahead and mark this lesson as complete.