Capture Net is an Item in Monster Hunter World (MHW).
A net that can be fired from your slinger. Use it to capture small creatures.
How to get CAPTURE NET
A key item given to all Monster Hunters by the commission, you should already have it in your inventory by default. Navigate to it in your hotbar on lower right hand side. Hitting Square / X / E will equip and unequip the Capture Net, and it temporarily replaces your Slinger. Press L2 / LT / C to aim and R2 / RT / Left Click to fire.
Your regular small slinger aiming reticule is replaced by a larger white rectangular reticule. See Example Image Below.
Try aiming at things in the environment - if something is in range and able to be captured, the reticule will change from grey to a sort of dull orange/red color.
Certain small creatures can be captured this way; along with special creatures / fauna like The Wiggler.