How do I place or remove birds and eggs?

To place an egg, tap an empty cell once. To place a bird, double-tap a cell.

Tap an egg again to remove it. Birds can't be removed once placed correctly, and neither can the eggs that were already on the board when the level started.

You can also swipe across empty cells to place several eggs at once. To erase eggs you've placed, start your swipe on one of them.