Attack (or escape) of the soft plastic bait

Take a look at the picture below:

That's my fishing tackle box, with something strange 'escaping' from the bottom. Taking a closer look:

One of the soft plastic worms that was loose on the bottom of my tackle box has eaten through the plastic base!

At first I thought it was melted by heat - maybe I had left some matches in there and they caught fire, or it had rested against something hot - but there is also damage to a different plastic container that contained some soft bait.

You can see in this picture that the worm on the right, and some of the bait on the left have started to dissolve through the clear plastic container. The picture below shows the right side a little better.

Seems a little bizarre to say the least...and I have to admit that these have been in my tackle box for probably close to 30 years(!) so they have had time to plan and execute their escape.

(Update: OK - closer to 40 years but don't tell anyone)

Checking the internet, this discussion makes sense...the compound that keeps the bait soft can also eat away at other plastic (like your tackle box).