We don't know how Noah managed to keep or control all this animals in the ark, and we never will because we are not Noah.
Or how they all fit on the ark, or where all the water got to, or how the ark could manage too survive these conditions, or how marine life survived the change of salinity, or how such a flood left no geological evidence, or how our genetic diversity would not allow for any fewer than a population of 10,000 people to exist yet we all came from 8 people, or how we got the genetic diversity of any of the other species on the planet for that matter, or how so many cultures only a few generations removed from this even just completely forgot about not only this happening but God as well, ...
But the Bible never told us to understand this, it just told us to belive it.
Worse yet it's asking this without providing evidence, which is despicable.
The Bible is not a fantasy,
"Fantasy is a genre of fiction that commonly uses magic and other supernatural phenomena as a primary element of plot, theme, or setting" -wiki
It doesn't appear to be distinguishable from fantasy.