Why are snails active when it rains?

Land snails are active when it rains. 

They must keep their bodies moist to survive. The human body consists of 60% water, but the bodies of snails consist of about 80% water. If the weather is hot and dry, their bodies will shrivel up and they will die. 

Their shells protect them from the weather. Summer is too hot and dry, and they could die in the heat so they stay inside their shells. Winter is too cold with too much rain on the ground so they hibernate or estivate in their shells. Land snails cannot breathe under water, so they don’t like flooded areas. Whenever they are in their shells, they seal the opening of their shells with mucus that dries, making it act like a plug or a door.

Snails move across damp surfaces more easily than dry surfaces, especially walls, stone pathways, bricks, roadways, and other flat surfaces. If the grass is too wet, it is difficult to slide across. For dry surfaces, snails need to produce more mucus – the ‘trail slime’ that can be seen behind them – so they prefer surfaces that are damp and moist.

Also, because snails are nocturnal – active at night – some scientists think that snails like dark rainy days, thinking it is almost night time.

Snails breed in the rainy season. They breed when the temperature is ideal – warm and wet – which is why they like spring time. 

Snails need damp soil to lay their eggs. They are oviparous and lay 100-400 eggs per year, but only when the temperature and conditions are ideal.

Location of photographs: Paris, France

Photographer: Martina Nicolls 

Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM