Forum showthread.php causing high server load??

[محروم.كوم]

My hosting provider said that the script "showthread.php" is causing a high server load. And they suggested:
Quote:
adding some sort of caching mechanism, where the script does not need to generate a new page with every request, helps to lower the over load that a script will cause.

My forums get daily visitors and posts, however not nearly enough to cause an overload on my hosts server. However I've always noticed TONS of bots on my forums. I've fixed the issue with them posting and registering, however they are also viewing threads. There'll be sometimes 10 registered users online and like 30 unregistered(mostly bots, I'm guessing) on the forums. Do you think that may be the reason, and if so, what can I do to prevent them from viewing threads and causing such a high server load. __DEFINE_LIKE_SHARE__