Early in the game captured predators like lions can be traded for cash. Try to sell them immediately to free up warehouse space.
Uncollected Products
Remember to never leave any products uncollected as they will disappear if you don't tap on them quickly enough making them a waste of time and potential profit.
Warehouse Space
Always upgrade your warehouse space whenever possible so you have some extra space to play with because if your warehouse gets filled up you won't be able to store any more products.
