Macbook pro need for antivirus and anti keylogging software?

l heard it is unnecessary to have it, but surely it would do no harm if had it running?
For anti keylogging software, l always use 'safekeys v3' to login to accounts with my PC laptop, is it necessary for macs? if not why not? since nothing is 100% , surely at the minimum using safekeys does reduce your chance of being key logged and also having an antivirus like AVG ?

I use Sophos anti-malware software on my MBP and it has so far detected and neutralised two attacks. Macs are vulnerable to viruses, just not as vulnerable as Windows. Sophos for Mac is free.

Read the forum sticky

http://www.mac-forums.com/forums/sw...-official-antivirus-malware-firewall-faq.html

Very useful thread - thanks.