'infatuated with life' - Stanford Intellectual Vitality

I just spit this out and will probably proofread it tomorrow, but it doesn't hurt to post it beforehand, right?

Stanford students possess an intellectual vitality. Reflect on an idea or experience that has been important to your intellectual development.

Curiously picking apart the owl pellet as my other classmates gagged on the musty odor; pouncing on crickets in the garage and stuffing them into a plastic cup filled with rice, wondering if they'll eat it; grabbing a scuttling lizard by the tail so that my cousin could snap a picture of it (and staring at the flailing tail in surprise when the lizard detached itself); I am fascinated with animals. As a child, all the books I read contained animals: My Side of the Mountain, How to Draw 50 Animals, and countless animal information books. However, this love for animals was checked when I enrolled for AP Biology. What did animals have to do with amines and carboxylic acid? AP Biology was so much more than just a life science class that at first I was afraid to pursue biology as my major. However, as the year went by and I learned more about the anatomy of animals and how they functioned, I realized that the class, while difficult, was fun. The molecular section of the class was boring, but I slowly understood that it helped explain how animals were able to function. I was stunned by the complexity of life shown to me through AP Biologyïwhich made me love life even more. Through the course of the class, my love expanded to include not only animals, but plants, humans, and fungi as well. The staggering amount of information in the textbook and its promise that there was still much to discover encourage me to unearth the secrets of the world around me. I have become infatuated with life.

I'll be happy to proofread your essays ^_^

This first paragraph needs to be reworked on a whole other level. Semicolons can only separate lines that stand on their own. You're first three sentences cannot as they do not have a subject.

However, this love for animals was checked checked? when I enrolled for AP Biology.

Overall I think this needs a lot of work, it doesn't really make any sense. I'm sure once you proofread it yourself you can churn out a winning essay

Revised
Stanford students possess an intellectual vitality. Reflect on an idea or experience that has been important to your intellectual development

As a child, I curiously picked apart owl pellets as my other classmates gagged on the musty odor and fearlessly grabbed a scuttling lizard by the tail so that my cousin could snap a picture of it (and stared at the flailing tail in surprise when the lizard detached itself). Although being cool did play a small part, the main reason for these acts of bravado was because I was fascinated with animals. I eagerly consumed information books and became awed by an ostrich's speed and stamina and the intricacy of a wolf pack's social order. Animals were different and beautiful, and as a shy girl, I found interacting with animals to be much easier than with people. However, this love for animals was strained when I enrolled for AP Biology. What did animals have to do with amines and carboxylic acid? AP Biology was so much more than just a life science class that it made me afraid to pursue biology as my major. It was also the class I stressed about the most-AP Biology is currently the only class I have had to stay up until 3 AM for. The class was difficult and taxing, and yet I became fiercely passionate about it. As the year went by and I learned more about the anatomy of animals and how they functioned, I realized that the first few chapters, while boring, explained the basic principles of how life existed . I was stunned by the complexity of life shown to me through AP Biology-which made me love life even more. This summer, I jumped at the chance to help at the local animal shelter, but disappointedly discovered I had to be 18 to volunteer. Through the course of the class, my love expanded to include not only animals, but plants, humans, and fungi as well. The staggering amount of information in the textbook and its promise that there was still much to discover encouraged me to unearth the secrets of the world around me. I have become infatuated with life.

i seem to be shifting in tense a lot...help?
also, does the animal shelter even fit? is there a better place to put it?
red: awkward. help with wording?

I'm sorry that it might sound harsh but I have to say that as soon as i saw AP biology, i feel this would be boring.I heard that you'd better not write things about exams.Just my suggestion.

"of the existence of life", perhaps? You might want to replace the word "existence", but I cannot think of any fit substitution.