Ask Marilyn: Are Lobsters and Cockroaches Cousins?

B. Williams in Georgetown, Kentucky, writes:

Marilyn: A steak dinner and dessert are on the line. I say that lobsters are related to cockroaches, and my sister says they are not. Are they? I believe I am right and can taste the steak now. Thank you for settling this!

Marilyn responds:

They're both arthropods, but more than 80% of the animals in the world are arthropods. Mostly, they include insects, arachnids, and crustaceans. Cockroaches are insects; lobsters are crustaceans. Not exactly family! In my opinion, you should share the price of the steak dinner. Maybe your sister could buy the coffee. But nothing fancy: no cappuccino!