Piece of Cake (vkirtsou, KostasTh)

It is a nice, sunny day and you have a picnic with your friends. You brought a mouthwatering cake, found the perfect place... but then insects arrive and try to gain a mouthful themselves!  You have to defend your cake!

What luck that one of your friends brought salt, ecological poison and zap lights with him. Place them wisely to defeat the waves of incoming ants and bees!