Ken Ham is Vice-President of Answers in Genesis, one of the most noted anti-evolution organizations. In a video presentation I saw, he said, If there were a worldwide flood, we would expect to find billions of dead things buried in rock layers all over the world, and that's exactly what we do find (ref: here).
This statement by Ken Ham is representative of perhaps the major problem of creation science, and it is the reason scientists call it pseudoscience. A similar example would be the statement that the Mt. St. Helens eruption released a lake, called Spirit Lake, the waters of which went racing westward to the sea, carving out a gorge one fortieth the size of the Grand Canyon in a few hours. Thus, it is possible that the Grand Canyon took just a day or days, rather than the millions of years that the evolutionists say it took.
True, the release of Spirit Lake does raise that possibility. Anti-evolutionists would like the argument to be left right there. They do not want to ask the question, Okay, it's possible, but is there any other evidence that will tell us whether it did happen?
With the Grand Canyon, there is evidence. Rushing water like that leaves a washboard pattern on the ground that it erodes. Anti-evolutionists know this, as I once saw a TV show hosted by Dr. Robert Gentry, who believes the Grand Canyon was formed by water released from a giant lake that used to cover much of Colorado, Kansas, Oklahoma, and even some of Texas. In a different show, he had described the washboard pattern that showed that the Spirit Lake gorge had been carved by washing water. What he neglected to mention is that the Grand Canyon has no such washboard pattern anywhere. The Grand Canyon was not formed by rapid erosion, as the Spirit Lake canyon was. There is evidence to settle the question.
The same is true of Ken Ham's billions of dead things statement. Yes, it's true that a worldwide flood would have deposited billions of dead things all over the earth, but that is not the end of the story. Would those billions of dead things be consistently deposited in the same layers and in the same order all over the earth? And if they would have been deposited this way, would they have been deposited in the order that we see all over the earth?
The answers to these questions is no. Trilobyte fossils are always under human fossils, never above them. The same is true of dinosaur fossils, whether those dinosaur fossils are large, big, slow or fast. Ken Ham has tried to explain this by saying that humans ran faster than dinosaurs, but did we run faster and get to higher ground even than pterodactyls, which could fly?
Would those billions of dead things have been buried both above and below 15,000 alternating layers of shale and sand with many burrows dug into the shale by animals and then filled with sand?
There are many more questions to ask other than just Would the flood have left billions of dead things buried all over the earth? Those other questions are too hard to answer, however. In fact, they are impossible to answer.