Skeptics have attacked the ark from several angles. None of their attacks have been valid. One such attack is a claim that the ark could not possibly house that many animals. Usually, they use the level of species or below as being equivalent to the biblical kind. That is not rational. Some skeptics calculate putting all the insects on the ark, but there were no insects since God commanded Noah to bring only the animals with breath in their nostrils. Other skeptics are ignorant as to the immense size of the ark.  They think it was rather small.  It was roughly 450 feet long, 75 feet wide, and 45 feet high.

Every species would not have been on the ark. The biblical "kind" is probably about equivalent to the scientific "family" taxon. There are many species in a family. For instance, wolves, coyotes, collies, foxes, and huskies are all in the same family: Canidae. You might say this is the dog kind, but a scientist would say that is the canidae family. House cats, lions, tigers, and bobcats are all in the same family: Felidae. You might say this is the cat kind, but a scientist would say that is the felidae family. The scientific designation of "families" are probably about equivalent to the original "created kinds".

How Could Noah and His Family Care for the Many Animals on Board the Ark?

The Microwave of Evolution

Do 'New Species' Demonstrate Darwinism?

The Real Nature of the Fossil Record