question about creating anti spam or bot questions

[Arantor]

I actually added auto-prune to the daily maintenance task on my stuff for that reason, setting a 3 day window for them.

[ayuub]

I use to have sow many spammer registering everyday I use to used numbers example 5+1 or 10+2

but since i changed my spam question in writing questions I start getting 0 spammers

Here is my sample
Q) How many days in July? A) 31
Q) How many days in a week?  A) 7
Q) What date is Christmas day  A) 25 December

This worked for me well

[Kindred]

Those are actually not good questions....

[Deprecated]

will a robots.txt file help keep bad bots off the site or is that useless?

Robots.txt is honored only by *GOOD* robots. The bad ones either don't read it, or they might even analyze it for places they are supposed to stay out of -- and look there first!

[Deprecated]

I saw in another forum that someone had questions 'what colour do you get when you mix blue and yellow?'  Everyone knows the answer is green, right?

Red and blue = purple, etc.

Bad question -- not everybody is an artist.

[Deprecated]

The best way to use this feature is to have a very large question pool. Even 20-30 questions is not unreasonable. Then present only maybe 3 questions at random out of your large pool.

The way spammers work on this challenge when you have 3 questions and ask them all, they register once by human and program the answers and next thing you have hundreds of new members. That actually happened to me, and over a few months I had to delete hundreds of accounts.

Instead select a big pool of questions, at least 20 up to maybe 30, but ask only 3 for each registration. That would take a huge number of attempted accesses for a human to get answers for your questions. How many? About 30 x 29 x 28 = 24K+ attempts to get asked every question of all 30 of them.

As far as how to get the right answer when the correct answer could be maybe '6' or 'six,' ask them this way:

Q: "What do you put your hat on? (4 letters)" A: "head"

You provide the information you need to get the correct answer in the question.

"What doesn't fit" questions work well too. Q: "What doesn't fit? up, down, left, backwards, green." (obvious answer)

It is also good to use questions that are specific to your forum theme. For a sports forum, Q: "what doesn't fit? Kings, Dodgers, Giants ... Crips." I'm not a sports fan (obviously) but Crips is an urban gang. Any sports fan should know there's no team named that.

Here's another one: Q: "Type this word backwards: spammer" (obvious answer)

Leave my post with this most useful idea. Have 20-30 questions to ask, but as ony maybe 3 at a time. Bot programmers will cry in frustration trying to get all your questions written down. Bots don't have a chance since they need answers programmed in.

I still have a few spammers but now they are all English speaking humans.

At some point if your 'bot registrations increase, change all the questions.