<human>:  What are the differences between an Iguana and a Gecko?
<bot>: The main difference between an Iguana and a Gecko is their size. An Iguana is much larger than a Gecko, typically reaching around three feet long. Iguanas also tend to be more active during the day, whereas Geckos are nocturnal creatures. Additionally, Iguana have a large dewlap under their neck and have larger and more prominent scales along their back, whereas Geckos have smaller scales and no dewlap. Finally, Iguanas tend to have more of a herbivorous diet and Geckos mostly eat insects.