Dumb question about stuff you see on arrakis

[Sardauker-Kirov]

"To be not eaten" How? they clamp theirself to the Teeth or Mouth :)

[Annaracl]

On caladan they have eagles hovering and yaks are seen in the first stage of harkonnen.There are three kind of yak,yak,yak hauder,and yak rider(you see yak rider in a stage of harkonnen where you have to kill the civillians. ;D ::) :'(

[Stormwatch]

In the book series When pardot kynes first comes to arrakis he see's water merchants with cows that are wearing special stilsuits Some freman had these as well

[Gunseng_Harkonnen]

"To be not eaten" means Fremen knows how to ride on worms without be eaten by them. I don`t belive you didn`t know :)