Nope, one does not need to defend the negative.

I don't have to defend a claim that there aren't rainbow colored unicorns that piss from the sky causing rain. I don't have to defend the claim that there isn't a fat cookie loving guy who rides reindeer once a year sliding down chimneys dropping off presents to children.

You must prove your affirmative, extraordinary claim. The burden of proof lies with him who asserts something. If you assert there is a god, prove it.

I can simply say, I see no proof of such a god existing so I don't believe he/she/it/they exist, just like the unicorns and santa claus. Bring me the proof and then lets talk.