Dododex
ARK: Survival Evolved & Ascended Companion

Tips & Strategies

Very useful! Easiest thing to knock out and tame, they act differently depending on the future weather (I.E. digging at the ground means a heatwave, barking/chirping is a sandstorm, growling w/ fluffy tail is a thunderstorm, and hugging their tail means good ole rain), their inventory weighs half when they're being carried, and most importantly, they look cute af when wearing hats.
More Jerboa Utility Tips
Despite past tips these little guys DO in fact reduce the weight of their inventory but it does not show in their weight stat, only when you pick them up. So say you are holding 100w worth of meat, and place it on your little fuzzy friend it may not show in their inventory as half (it will still show 100) but now when you pick them up you will notice your weight only goes up by 50, not the full 100 the meat weighed in your own inventory.
Basically, yes weight does half, but only when held! <3