How did every species find the ark? Targum Pseudo-Jonathan on (Genesis 6:20) gives an answer the Torah does not.

"Of the fowl after its kind, and of all cattle after its kind, and of every reptile of the earth after its kind, two of every sort shall enter to thee by the hand of the angel, who will take and cause them to enter to thee, to be preserved."

An angel. A specific angel, sent by God to round up pairs of every creature and deliver them to Noah's door. Noah did not have to hunt them. He did not have to send out messengers across continents. An angel brought them.

This is the Targumist's quiet theological point. The survival of biological diversity through the Flood was not a human feat. Noah built the shelter; God staffed it. The ark is a joint project: human labor and angelic delivery, each doing what only it can do. When the task is saving the world, the effort is always collaborative.