[Lo.Lee.Ta.]

It looks to me like each ring has 4 pi electrons, so it follows the 4n rule for being anti-aromatic.

It also looks like it's planar...


So, why is this molecule non-aromatic?

Thanks for the help. 

[Corribus]

First of all, polycyclic systems don't always follow Huckel's rule.  Second, there are two sp3 hybridized carbons that prevent resonance stabilization.