Proof that that animals can plan ahead? It's amazing the things we're learning about animals recently.
Orca that spit out their partially chewed fish food as bait for seagulls.
Dolphins that create and play with bubble rings. (Which hilariously is just now making it to the "mainstream" sews services.)
And now the monkeys and apes? And you know dogs and cats can plan. Lying in wait is totally planning ahead.