Why are wooden sticks usually used for ice cream bars?

This seems to hold for every commercial ice cream bar I have ever had, yet I can't find the reason... Why not use plastic instead, for example?

As for the wood material, it is belongs to the Low-carbon environment, in another words, as for the current ice cream industry, the ice cream sticks cannot be used for the repetition and recycle, it is not like the glass of bottle for the beverage or the yoghourt. The low-carbon refers to the capacity release of the the carbon footprint, the footprint of the growing wood material is negative value. So if the used wooden ice cream sticks can be recycle, they can be also used for make the paper and the synthetic wood.