Yes, you can add a captcha form to your survey. This may be done during the survey creation process.
You can also set a password that users must enter in order to access your survey; you can limit the number of participants who can take your survey; and much more. The options for customization are endless!
When you design and complete a form, you have the ability to access Javascript or the iFrame code to embed the form on your page, where customers will be able to fill it out.