After the death of the beloved Steve Irwin, many Americans were temporarily incapacitated by shock and grief.  Not being one of them, I have nonetheless resolved to do my part to help fill the gaping void left in the field of wildlife narration.

Today, I will instruct you in a crucial point in mammal differentiation: how to tell a First Semester Senior from a Second Semester Senior.

Those of you who consider yourselves studied in senior-spotting may scoff at my lesson.  Why, you might say, the way to tell a First Semester Senior from a Second Semester Senior is by whether it is second semester. 

Though the distinction may seem at first to be seasonal, both types of seniors can in fact be found year-round -- some become Second Semester Seniors by the end of their junior year and others become First Semester Seniors their sophomore year. 

Here are some methods to distinguish a First Semester Senior from a Second Semester Senior that will work at any time:

• A First Semester Senior always attends the classes of those teachers who are writing his recs.  A Second Semester Senior always attends classes when it's cold or raining outside and no good movies are playing.
• A First Semester Senior scrambles around the school, turning in forms.  A Second Semester Senior scrambles eggs at home during second period.
• A First Semester Senior spends eight hours trying to define herself in 500 words or less. A Second Semester Senior spends eight hours trying to define "hyphy" for the school newspaper.
• A First Semester Senior has coffee with college interviewers when he should be studying for a math test.  A Second Semester Senior has coffee with friends because the test doesn't matter.
• A First Semester Senior knows the SAT range of every college in the continental United States. A Second Semester Senior knows every channel on Direct TV.
• A First Semester Senior is red-eyed from lack of sleep.  A Second Semester Senior is red-eyed from too much sleep.
• A First Semester Senior scares freshmen.  A Second Semester Senior forgot freshmen exist.
• A First Semester Senior rules campus.  A Second Semester Senior wouldn't be caught dead on campus.

Now, in your spotting, watch out these other rarer breeds of seniors:

• The Early Accepted Senior is known for cockiness and is distinguishable from the Second Semester Senior only in that it appears earlier in the year. 
• The Early Onset Senior also resembles the Second Semester Senior: She still has another year of high school, but she has already adopted the mannerisms and values of a Second Semester Senior.  These seniors are occasionally welcomed into senior packs, but are also sometimes fended off or "put in their place."  The decision about whether to welcome or reject an Early Onset Senior depends on an ill-defined quality known colloquially as "coolness." 

Now that you've been informed, you're ready for some quality senior-spotting.  Good luck, and be careful.  Remember, the Second Semester Seniors are the friendly ones.

Rachel Wolf is a senior at Palo Alto High School. Her column, “Wolf Bytes,” is published on this blog the first Monday of every month.