I found this code that should redirect some bad bots and crawlers out of the site:

Code:
RewriteEngine On
RewriteCond %{REQUEST_URI} !/robots.txt$
RewriteCond %{HTTP_USER_AGENT} ^.*BLEXBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*BlackWidow.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Nutch.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Jetbot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebVac.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Stanford.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*scooter.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*naver.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*dumbot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Hatena\ Antenna.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*grub.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*looksmart.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebZip.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*larbin.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*b2w/0.1.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Copernic.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*psbot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Python-urllib.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*NetMechanic.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*URL_Spider_Pro.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*CherryPicker.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*EmailCollector.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*EmailSiphon.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebBandit.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*EmailWolf.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Email.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*ExtractorPro.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*CopyRightCheck.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Crescent.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*SiteSnagger.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*ProWebWalker.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*CheeseBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*LNSpiderguy.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*ia_archiver.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Alexibot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Teleport.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*MIIxpc.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Telesoft.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Website\ Quester.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*moget.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebStripper.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebSauger.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebCopier.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*NetAnts.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Mister\ PiX.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebAuto.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*TheNomad.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WWW-Collector-E.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*RMA.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*libWeb/clsHTTP.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*asterias.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*httplib.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*turingos.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*spanner.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Harvest.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*InfoNaviRobot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Bullseye.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebBandit.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*NICErsPRO.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Microsoft\ URL\ Control.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*DittoSpyder.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Foobot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebmasterWorldForumBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*SpankBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*BotALot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*lwp-trivial.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebmasterWorld.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*BunnySlippers.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*URLy\ Warning.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Wget.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*LinkWalker.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*cosmos.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*hloader.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*humanlinks.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*LinkextractorPro.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Offline\ Explorer.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Mata\ Hari.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*LexiBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Web\ Image\ Collector.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*The\ Intraformant.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*True_Robot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*BlowFish.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*SearchEngineWorld.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*JennyBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*MIIxpc.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*BuiltBotTough.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*ProPowerBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*BackDoorBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*toCrawl/UrlDispatcher.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebEnhancer.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*suzuran.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*WebViewer.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*VCI.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Szukacz.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*QueryN.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Openfind.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Openbot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Webster.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*EroCrawler.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*LinkScan.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Keyword.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Kenjin.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Iron33.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Bookmark\ search\ tool.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*GetRight.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*FairAd\ Client.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Gaisbot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Aqua_Products.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Radiation\ Retriever\ 1.1.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Flaming\ AttackBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Oracle\ Ultra\ Search.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*MSIECrawler.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*PerMan.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*searchpreview.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*sootle.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Enterprise_Search.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Bot\ mailto:[email protected]*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*ChinaClaw.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Custo.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*DISCo.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Download\ Demon.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*eCatch.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*EirGrabber.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*EmailSiphon.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*EmailWolf.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Express\ WebPictures.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*ExtractorPro.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*EyeNetIE.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*FlashGet.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*GetRight.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*GetWeb!.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Go!Zilla.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Go-Ahead-Got-It.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*GrabNet.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Grafula.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*HMView.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*HTTrack.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Image\ Stripper.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Image\ Sucker.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Indy\ Library.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*InterGET.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Internet\ Ninja.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*JetCar.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*JOC\ Web\ Spider.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*larbin.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*LeechFTP.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Mass\ Downloader.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*MIDown\ tool.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Mister\ PiX.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Navroad.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*NearSite.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*NetAnts.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*NetSpider.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Net\ Vampire.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*NetZIP.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Octopus.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Offline\ Explorer.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Offline\ Navigator.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*PageGrabber.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Papa\ Foto.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*pavuk.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*pcBrowser.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*RealDownload.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*ReGet.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*SiteSnagger.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*SmartDownload.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*SuperBot.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*SuperHTTP.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Surfbot.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*tAkeOut.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Teleport\ Pro.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*VoidEYE.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Web\ Image\ Collector.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Web\ Sucker.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WebAuto.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WebCopier.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WebFetch.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WebGo\ IS.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WebLeacher.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WebReaper.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WebSauger.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Website\ eXtractor.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Website\ Quester.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WebStripper.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WebWhacker.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WebZIP.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Wget.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Widow.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*WWWOFFLE.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Xaldon\ WebSpider.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Zeus.*$ [NC,OR] 
RewriteCond %{HTTP_USER_AGENT} ^.*Semrush.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*BecomeBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*AhrefsBot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*MJ12bot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*rogerbot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*exabot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Xenu.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*dotbot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*gigabot.*$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*BlekkoBot.*$ [NC,OR]
RewriteCond %{REMOTE_ADDR} ^45\.117\.156\.154 [OR]
RewriteCond %{REMOTE_ADDR} ^164\.132\.192\.23 [OR]
RewriteCond %{REMOTE_ADDR} ^62\.210\.148\.119 [OR]
RewriteCond %{REMOTE_ADDR} ^150\.107\.4\.13
RewriteCond %{REQUEST_URI} !^/allowedbyallips\.html$
RewriteRule ^(.*)$ http://pastebin.com/9dPXX0D9 [R=307,L]
http://pastebin.com/9dPXX0D9 can be replaced by some URL where bad bots will be redirected. The IPs that are on the bottom can be ones that are not welcome and also will be redirected.

More effective solution to minimize traffic wasted by the bad bots is to use tools like zBBlock or CIDRAM. Downside of these is that they will block from time to time also valid site visitors. (Blocked visitor can be given chance to contact admin via e-mail or just fill the captcha in case of CIDRAM)

Here are another htaccess rules that can block more dangerous bots/people (hackers, exploiters): https://github.com/alidbg/htaccess_firewall