

In a scientific face-off, Mark goes head-to-head with NileRed and Kevin the Backyard Scientist to find out which is more destructive: acid or lava.

To stop the sneaky squirrels from raiding his bird feeder, Mark builds a challenging eight-part obstacle course in his backyard to try and slow them down.

Mark throws an epic birthday party for a deserving teen, complete with record-breaking devil's toothpaste experiment - the first of its kind.

Step right up and learn which carnival games are actually winnable and which ones aren't, courtesy of Mark... and a friend from the New York Mets.

Mark's robot Dom is really good at setting up dominos. But can he fill a warehouse with a mural made up od more than 100,000 of them in just 24 hours?