Read the colored meadow boundaries.

Every colored region is one meadow, regardless of its size or shape. Each meadow must contain exactly one firefly.

Five colored meadows, whatever their shape. Each one holds exactly one firefly.

Place one firefly in every row.

Each horizontal row contains exactly one firefly. Once a row has its firefly, every other square in that row can be marked impossible.

With its firefly placed, the rest of this row is empty.

Place one firefly in every column.

Each vertical column also contains exactly one firefly. Row and column constraints work together to narrow each meadow’s possible squares.

The same goes for its column.

Do not let fireflies touch.

Two fireflies may not occupy neighboring squares, including diagonal neighbors. Mark the eight surrounding squares with × after placing a firefly.

“Give every light some room and the whole meadow starts to sort itself out.”
Halley

Clear all eight neighbors

Not allowed

Touching at a corner counts as touching.

Mark deductions and complete the field.

Click a square to cycle Firefly → × → clear; right-click marks × directly. The puzzle completes when all row, column, meadow, and separation rules are satisfied.

A finished field: one firefly per row, column and meadow, and none touching.