How Were the Animals Gathered?
"Bring a pair of every kind of animal—a male and a female—into the boat with you to keep them alive during the flood. Pairs of every kind of bird, and every kind of animal, and every kind of small animal that scurries along the ground, will come to you to be kept alive. And be sure to take on board enough food for your family and for all the animals.” (Gen. 6:19-21, NLT)
The Genesis passage clearly states that God gathered the animals and brought them to Noah inside the ark two by two.
We know that most animals possess the ability to sense danger and to move to a place of safety. In the time of Noah, God had two air-breathing land animals of every kind travel to the very spot where Noah was building the ark just before the flood came. Aquatic mammals, insects, worms, and fish could survive in the water and did not need to be on the ark.
God designed the Ark to be strong and to stay afloat. It probably resembled a floating barn or stable.
ChristianAnswers.net explains that as many as 50,000 animals (including creatures that may now be extinct) could have fit on board the ark. These would not have needed to be the largest or even adult specimens.
They point out that there are really only a few very large animals, such as the dinosaur or the elephant, and these could be represented by young ones. "Assuming the average animal to be about the size of a sheep and using a railroad car for comparison, we note that the average double-deck stock car can accommodate 240 sheep. Thus, three trains hauling 69 cars each would have ample space to carry the 50,000 animals, filling only 37percent of the ark. This would leave an additional 361 cars or enough to make 5 trains of 72 cars each to carry all of the food and baggage plus Noah's family of eight people."
The Ark was large enough for all of these animals, for Noah and his family, for all the food and supplies needed for a year-long journey.
Noah and his family cared for the animals on the ark every day as part of their daily chores. It must have been an exciting place to live!
So God brought the animals to the ark, and Noah's family took care of them until it was safe to go back into the world.