What makes this weird marking on wood?

[GayJerk]

Someone on Instagram posted this image asking what insect (assuming it is one) made these tracks? It's on wood and appears to be eating the film on top of it. Any leads would be welcome, it's really bugging me that I don't know haha. 

 

[Viking]

It looks like snails tracks to me. It l looks like algae is scraped off.

 

[MantisGirl13]

It looks like snails tracks to me. It l looks like algae is scraped off.

If it were snail tracks, why the zig zags?

- MantisGirl13

 

[Viking]

It is like moving the lawn. They are eating not trying to go to a destination. I have seen a similar patterns on the side of house in Louisiana. It is wet with algae everywhere.

My snails in aquariums do this. Also slugs behavior the same.

.It is definitely something eating algae.

 

[GayJerk]

It is like moving the lawn. They are eating not trying to go to a destination. I have seen a similar patterns on the side of house in Louisiana. It is wet with algae everywhere.

My snails in aquariums do this. Also slugs behavior the same.

.It is definitely something eating algae.

Cool thank you!! I was thinking that too!