Here's the wrong question to ask:

How did all the animals fit in the ark? 

The most crucial question of Genesis 6 is NOT about the animals. Not at all.

Rather, it is this: why was an ark needed in the first place?

In other words, why was God willing to flood the entire globe, only six chapters after creating it? Seems drastic.

So why did God do it, and what does it tell us about the future?

Questions That We'll Answer:

A) In what way did the flood typify the wrath of God being 'poured out?'

B) In what way did the ark typify Jesus Christ? Is Jesus in this text?

C) Why did Christ refer to future days as being 'like the days of Noah?'