My wife and I take in homeless cats. You would not believe the food and water we go through feeding about twenty or thirty cats (and also the medicine we go through treating them). I can't imagine the food and water it would have taken to feed all the animals Noah would have to have taken in order for us to have the variety we have today.
The story is just so difficult to believe. What about, for example, all the different varieties of fish that are so sensitive to different levels of salt in water, temperature of the water, etc. It's difficult sometimes to keep certain fish alive in aquariums even with all the knowledge we have available today, the water testing equipment, chemicals, etc. How could all the different varieties have survived a worldwide flood?
What about all the different types of venomous snakes, insects, lizards, frogs, birds, plants, etc.? What about the platypus, the electric eel, etc.? How would Noah have even known whether he had representatives of all the animals? How did he know what types even existed? He had obviously only experienced a small part of the earth. Did he have some kind of catalog of all the types of animals that existed? Are we to believe that he knew of every type of animal that existed in his day? We are still discovering new species today.
I want to believe the story because I want the Bible to be true, but it's very difficult for me to believe it.