As a result of bot usage increasing rapidly I designed a set of OSRS Items testing and catching bots to determine if the player is actually a bot. While training, some users prefer to visit different sites. I took that into account when designing my tests. Failure to pass a test doesn't necessarily mean one is a bot. However, they are more likely than others to fail it.
You can reach them and ask "Are you bots?" You will most likely get an answer although they might be talking (they now have chatbots). But, there is some bots that do not respond. To determine if they are really botting and not just afk, ask them when they are banking or changing trees/rocks. If the person you are asking is not able to respond, add 3 to the "suspicion meter".
Ask them a trick or ask them questions. Ask their level of mining if they're fishing. If they're mining, inquire about their magic level, ect. etc. If they are caught or do not respond at all Add 1 to the suspicion meter. Follow them around. Are they able to admit that they are following you? Add 4 "suspicion meters" If they don't.
Examine their patterns. Do they respond immediately to a fallen tree, or a revived ones? Add 2 to the suspicion meter. Examine their habits of clicking. Are they clicking in the exact same places each time they visit a the bank to deposit their money? If yes, increase the suspicion meter by 4.
It is possible to do something unusual that attracts the attention of Buy OSRS Fire Cape others. If they don't respond, they may be either botting or afk. Try hitting them with an easter-themed carrot or throwing snowballs at them to see if they can get an immediate response. Add 4 to your suspicion gauge.