CAPTCHAs annoy real people. A honeypot is an invisible field humans never fill but naive bots do.
Bots that crawl for forms tend to fill every input. Add a field hidden with CSS; if it arrives filled, it's a bot. FormDrop checks a field called botcheck and silently drops such submissions — the bot even gets a success response, so it doesn't retry.
<input type="checkbox" name="botcheck" style="display:none" tabindex="-1" autocomplete="off">Use tabindex="-1" so keyboard users never land on it.
Honeypots stop the bulk of automated spam, not a human pasting spam by hand or targeted bots that render CSS. If you still get spam, add server-side keyword filtering in your email client or a CAPTCHA as a last resort.
Not when hidden with display:none and removed from tab order.
No.