I would like to add to the very good comments by BU.
We should not take kids for granted nowadays due to the amount of info that is freely accessible to them. I don't think explanations like birds and bees which was std advice decades back will work in present day. Kids get lots of info and education not only from us but from their peers , media and other influences.If we do not explain correctly, or take time to address their questions well, chances are they will slowly not trust us and start being influenced by other sources of info. An example is when Buddhists cannot provide a good response to people who accuse us of praying to idols and statues. Without a convincing explanation, they will find answers elsewhere which may reinforce their doubts.
Keeping the statues or imagery covered as in public places of worship , temples etc , is appropriate. In our homes, there is no risk of disturbing the sensitivities of others as we can have lots of time to explain and educate our family members or even friends who visit.