Is this normal: 123 guests/spiders?

[mjames]

I have about 7 members and 123 guests online, and many of them are lj2541.inktomisearch.com or similar. It seems this is the same spider always on there and I fear it's hogging bandwidth and slowing the site down. I don't mind a few, but six pages of this? Is this normal? And how do I stop it?

[mjames]

Looks like it's the Yahoo! "Slurp" spider and this is not uncommon. I am going to add this to robots.txt to slow it down:

User-agent: Slurp
Crawl-delay: 30

Not sure what delay to use, any suggestions? Also, will putting robots.txt in my root directory still work for my forums in another directory?