a good question Jonah, and one that is pondered by those in the Body and those seeking to justify their rejection of God
i don't have the answer, only more questions and the faith that God's mercy was at play
I think that's part of it, but I think that there's more to it than just "how many babies did God kill with the flood?".
I think a better question to ask is, "how many babies were there just before the flood?"
See the link below for why I say that...
"God's mercy"? Sure, let me drown a 6 month old. And before I get banned for daring to ask that question---
You're not going to get banned for asking questions. Only if you're disrespectful. So don't be disrespectful.
failing to ask it shows a lack of moral courage if you believe in a historical Noachian Flood. Does not really put your deity in a very merciful light.
I think your frame of reference is wrong, and is therefore causing you (perhaps willingly) to accuse God of injustice.
But I guess we can write it off to "We just can't know everything about the Christian god".
I think in this case, it's pretty easy to figure out.
But still no response to the other question, How many people were killed in the Flood, and the next question---where are all those fossils.
The answers to your questions, "Why did the infants have to die?" and, "Anyone have any idea of the size of the human population just before the Flood?" and, "Where are all those fossils?" are found here:
http://www.creationscience.com/onlinebook/FAQ225.html#wp16506776