Normal sudoku rules apply. SNAKE: Draw a snake, one cell wide, that starts and ends at two neighbouring cells within the same 3x3 box. The snake only moves orthogonally, and visits every cell in the grid apart from the large grey rock in the central cell. The snake may not enter any cell more than once. INSECTS: The snake must eat every insect, and these divide the snake into segments. Adjacent segments along the snake have consecutive totals. No two segments have the same total. GREY PEBBLES: The snake must not pass directly through any grey pebbles. Digits joined by a grey pebble are either consecutive, or have a 1:2 ratio (so one digit would be double the other). EGGS: One of the four digits surrounding an egg indicates the number of spots on that egg.