Apart from red fanta, a clump of bananas are often placed on an exterior wall to placate evil or angry spirits. Birds love this idea.

Anyway, I don't think it's accurate to call this a Buddhist practice. Probably more animist?

Since this thread has evolved to helping us understand these strange (to us) things about Thailand

Can anyone explain why they take the old spirit houses and dump them on the side of the road ?

Does someone just dump one, and then everyone knows that this is the new spot to dump theirs ?

An Elephant wont sit on a Wall like a Red Fanta.

Anyway, I don't think it's accurate to call this a Buddhist practice. Probably more animist?

Thais are strongly animistic with a veneer of Buddhism. everything has a spirit form and an earthly form, spirits are happy with the form not the physical essence, so you get paper objects and spirit money being offered, just like the Chinese do. In a group of drinkers a small libation poured on the ground is a common sight at the start of a session.

For some reason spirits prefer spirits to beer

It's not just red Fanta, other flavors are used too. As well as bottles of water, Pepsi, shot glasses of whiskey, coconuts, and all sorts of other drinks.

In a group of drinkers a small libation poured on the ground is a common sight at the start of a session.

Gotta pour one for your homies

Silly people, Don't they that red drink will only make him hyperactive

Can anyone explain why they take the old spirit houses and dump them on the side of the road ?

They end up near magic trees, and these trees are often on the side of the road.