Origami Earwig

When chilling in the garden, I saw an earwig. Of all the origami that I have seen, I didn't remember seeing earwig in origami except by Brian Chan. Therefore I decided to give it a try.

Design

I had just learned about the 22.5 degree method, so I wanted to practice it.
Starting from the stick figure:



An insect model is typically seen from above. Therefore, we need to make sure that the model can be spread left and right. This can be done by adding tiny flap for every joint, as shown as thick blue stubs in the picture above.

The creature is long, which is why I think diagonal symmetry would work well. For the next pictures, I will omit the diagonal half.

Start with the antennae, using bird base. The top left corner flap will not be used, and the middle flap will act as the stub for the model's spreadability.




Next, I needed a gap before placing the legs. This is usually done using "Y molecule". It also provided 2 flaps which I used for the first 2 legs. The other molecules were improvised to fill the spaces while also keeping the leg flaps' length valid.


At that point, I had no idea how to continue filling the papers. Therefore I casted 22.5 degree lines from the intersection points, hoping to get inspiration.


That was helpful, I figured out half bird base can be added for the final leg. We could also close the paper's length here, since the only part left were the abdomen and pincer. There should be enough paper for those parts.
 

I used "Y molecule" again and a sawhorse molecule to provide gap between the legs and pincer. This gap will become be abdomen. One final piece is the pincer, to be put in the area marked with "?".



The problem statement is: given a square paper, how can we create a pincer with jagged edges?
To solve it, I picked a paper and going for trial and error.

First, forget the jagged edges and start with the pincer. This is easily done using fish base, which is sunk to allow spreadability.



To make a pair of pointy edges, I added smaller flaps right beside the long flaps. This leave the remaining unused paper in a square shape, as marked with "?" below.
 

To add more pointy edges, we can recursively add the same pattern again. The idea of using fractal structure is something I learned from Jun Maekawa's turkey.




Now it has two pairs of edges in the pincer. Even though it may not be anatomically accurate, it should be representative enough.

Now the crease pattern is complete. I did some calculations, and the proportion is the classic \(1 : \sqrt{2}\).

There are some adjustments:

1. The unused flap on top left corner now get used for making mouth parts, by splitting it.
2. All the "Y molecule" is replaced with rabbit ear fold. The reason is some sink folds are needed to narrow the legs, and sink fold on "Y molecule" is not easy. 

Fold

Again I used the craft paper I bought from Daisho, with 30 cm x 30 cm size.

Remark

I had a dejavu, feels like I have seen this design before. I realized that this design turns out to be very similar with Robert J. Lang's silverfish. Due to the similarities of both creature's body plan, swapping the pincer's crease with frog base will give you silverfish. I guess this is another analogy of "convergent evolution" where efficient design may be developed independently.

With this similarity, I am not very proud of this design. Anyway, at least I was able to practice the 22.5 degree method.