This stupid caterpillar of probably Papilio demoleus is desperately trying to kill my lime plant outside my house!
Found out that it's in its 4th instar

Chomp chomp chomp
There goes my leaves
The yucky worm just makes my skin creeped
(Wow, it rhymes!)

My poor plant now is desperately trying to save itself
Continuous production of chemicals to deter feeding behaviour
So remaining leaves can still grow & photosynthesize

But caterpillar is not happy
It wants to eat to grow into a beautiful butterfly
It evolves overtime to produce chemicals that detoxify the toxins produced by the plant
or specialises its digestive system to enable toxic food consumption

Plant is not happy again
Spending so much energy producing deterrent to pests
Now it has to coevolve again to overcome
So as to increase survival of the fittest

Caterpillar is not happy again
So is the plant again

Again & again
Coevolution takes place on & on
Chemical warfare proves better & better
None of them choose to die

Interesting chemical ecology