It's a mail bag episode! While Lindsay is away, Marshall is going through a bunch of listener questions and answering them as best he can. Do monkeys get ice cream headaches? Why is Play-doh so salty? Listen to find out the answer to this and more in this special episode of Tumble. If you want to submit a question for Marshall & Lindsay to answer, go visit our website at http://sciencepodcastforkids.com.