A second bird bath is filled with water splashed out of the higher First bath. So the thing stays filled longer.
Our bath here can be a third emptied by just few birds doing their normal bathing.
The benefit of such a bath is you do not have to check and refill it so often.-- popbottle, Nov 09 2014 I couldn't resist.. https://www.google....08%252F%3B500%3B403 [not_morrison_rm, Nov 10 2014] You could fill the bath with transparent fibreglass resin instead. Once it sets, it'll look fine but the birds won't be able to splash the stuff out.-- MaxwellBuchanan, Nov 09 2014 But without birds, the bath will not attract cats.-- popbottle, Nov 09 2014 If you time the resin to set at the right moment, there will be birds.-- MaxwellBuchanan, Nov 09 2014 Good intention. +-- blissmiss, Nov 09 2014 If the resin is sticky enough, there will be cats too-- hippo, Nov 10 2014 <quiet evil sniggering>-- 8th of 7, Nov 10 2014 random, halfbakery