Complex sentence: The hole for the entrance is approximately 1.2 cm and the tunnel is around 1.2-1.6 cm wide, while the length of the tunnel is about 12 cm or more long.
Split into simpler sentences: The hole for the entrance is approximately 1.2 cm wide and the tunnel ranges from 1.2-1.6 cm wide. The length of the tunnel is about 12 cm or more long.