My iguan shakes her head up & down when asked a yes or no question this sounds stupid but ......?

Question

has anyone ever had this happen, or knows why they do this?

Answer 1

Iguanas are actually remarkably intelligent. While bobbing is generally used as a territorial sign, your iguana may have picked up your favorable reaction to it's behavior, and is repeating what it deems a "positive" behavior.

That's really cool.

Answer 2

It's normally a territorial thing.

Here is some helpful info:

They should be feed:

45% leafy greens such as escarole, dandelions, endive, mustard, and collards, NO lettuces or spinach! They aren't good for him.
45% hard mixed veggies such as an orange flesh squash the harder the better(acorn,pumpkin,butternut... fresh green beans, fresh peas, parsnip, and green bell peppers, NO broccoli or cauliflower, or avocado!
10% fruit such as figs, papaya, mango, pear, and berries. NO bananas, only very rarely as a treat.
NO ANIMAL PROTEIN such as bugs, meat, eggs, or cheese!

Temperature:

They need a basking area of 95-100 and normal temps of 75-85. NO heat rocks!

Lights:

They need a 5.0 UV light.

Hydration:

They should also get baths everyday or so. And should have a water bowl in their cage.

Vet:

You should take Your Iguana for regular vet checkups to make sure it is in good health. Reptiles can have internal parasites that can harm them so you should make sure the vet checks that.

Here are some good sites, the first one was recomended by my vet.

http://www.anapsid.org/iguana/index.html
www.greenigsociety.org
www.triciaswaterdragon.com/igcare.htm
http://www.baskingspot.com/iguanas/igbook/
http://www.reptilecare.com/IgCare.htm

Answer 3

All iguanas will do this to some degree - males do it more often than females, and females tend to have a more "jerky" bobbing.

The main reason they do this is a show of aggression ("I'm the boss here") or territoriality ("Back off! This is my space - I was here first!). Here's a resource that has info about head bobbing - if you go back to the home page, there's all kinds of info about iguanas and other reptiles & amphibians: http://www.anapsid.org/iguana/bobbing.html