A short matchsick glued into four 'corners on the inside of the lid stops anyone from screwing the lid tightly and preventing air from entering the jar.
Call it a spacer.
Ok - makes sense
I bought this worm container way back in the 80's in the USA - and have used it more times than I can count - mainly on the Zambezi. Excellent for keeping worms cool and fresh for each days outing. It opens on both sides. I have had to repair this box many times (as you can see!) but it is still functional after all these years
On long trips camping in the Zambezi valley - we buy many worms and rig up an ant proof worm farm hanging from a tree (to keep the ants away) and decant a load for each days fishing. The worm farm consists of a hessian sack with the worms and a mix of grass and leaves with soil. We keep it wet using a bottle of water with a wick on top of the sack so that the worms are always moist and the breeze keeps the damp sack cool. the sack is placed in a shopping basket. We manage to keep the worms fresh for 10 days easily. Occasionally we go through the sack and remove dead worms - dead worms create more dead worms.
In the pic of the "worm farm" you can see another worm container for daily use - made in Zim - but not as effective s, it is made of wood and heats up fast and moisture causes the box to warp and come apart
I have been looking for a replacement for my Yellow box - but have not seen one in SA
