Why didn’t Noah collect them up?
They didn’t respond to the announcements.
How did Noah collect the kangaroos in Australia?
If you mean, did he take some on the ark - the Bible gives a list of all that he was commanded to take - and God brought the animals to him. Ultimately, we don’t know but findings from different cultures all over the world show evidences of ‘dragon type creatures’ in literature and art. It’s a person’s worldview that matters. Naturalists believe there is only matter and so they look for evidence that confirms their worldview and reject evidence that doesn’t. Scientists that are Christian or hold that worldview do the same. Do you know about a scientists named Dr. Nathaniel Jeanson? He has some powerful genetic evidence of people groups from all over the world (and it’s growing and secular scientists have contributed greatly to this body of evidence). He traces genetic changes through the male T cells. It’s extremely interesting and gives a very different view of the spread of humans over the earth. The beauty of it is that it’s evidenced based and can be extrapolated back in time. It’s pretty powerful in it’s implications. Secular scientific publications will almost never publish these findings. It has nothing to do with science but bias. The problem with people is that we hate what the Bible has to say about us. We like sinning. It comes very natural as does most selfishness. We are asked to fight our nature. We don’t like that. I’m also guilty. But the evidence is on the side of the Bible.
https://www.youtube.com/results?search_query=dr+nathaniel+jeanson+
Here’s another great site https://www.youtube.com/watch?v=DCHJbO-3-jA
This guy is a cold case detective from LA. His family are atheistic but he became a believer because he applied his investigative skills to the gospels. It’s very interesting - even if you choose not to accept any of it - but he shows beyond a doubt that the gospel evidence is reasonable. He’s very thorough. I hope you give it a spin. Our culture is spiraling out of control. Having an anchor for your soul will become increasingly important as we become Sodom.
Probably off fooling around, like the unicorns.