If you do these exercises too, you will learn a crapload of good stuff.
Control of Negative Spaces gives you needed contrasts.
Contrasts in filled spaces VS empty spaces. If every part of an object is about the same size and distance from every other part, the whole object becomes harder to see - because it becomes a bunch of equal separate parts.
Bugs has a very tricky head shape. It isn't a oval. It has multiple planes that you have to understand and memorize and then be able to figure out they would look like from different angles. This was even hard for the animators in the 1940s.
YE GODS ! Rare Kali Sketchbook For Sale!
http://kalikazoo.blogspot.com/2009/01/ebay-auction-sketchbook.html
If you are the lucky dog who wins this ebay auction, not only will you not only have hundreds of original drawings, paintings and marker treats, but Kali herself - THE KALI- will inscribe a personal note to you and you can show it off at church next Sunday and make all the other congregants envious, then God Almighty in His infinite wrath will send them straight to to Hell.
Bonus: Free Rex and Katie drawing!!