If by level 1 you mean the scorpions level, then yes.
No I mean it like this:
You are level 1,
The scorpions give full xp.
You are level 2,
Scorpions give 95% of their xp.
You are level 3,
Scorpions give 90% of their xp.
etc etc (just an example)
Other critters dont degrade till a certain level, and other critters never have degrading xp.
That's the xp system I had in mind.