Snails, as cold-blooded animals, are sensitive to changes in atmospheric humidity and temperature. Giant African Land Snails (GALS), especially Achatina fulica, are able to put up with a range of conditions, but when temperature and/or humidity are not to their liking, they go into dormancy. The snail retracts its entire body inside its shell, sealing off the opening with a white, calcareous layer to prevent water loss from the body. This reaction is typical of all snail species.
Snails aestivate if the temperature is too high (greater than 30°C), or if air humidity is too low, (lower than 70-75% relative humidity). Snails hibernate if the temperature drops below 5°C.
For the snail farmer the result is the same: his (or her) snails become inactive and stop growing, losing valuable growing time, while expenses for housing, tending and protection continue.
Consequently, it is in the snail farmer’s interest to prevent, or at least reduce, dormancy
- by selecting the most favourable site for the snail farm
- by providing good housing for the snails
- by providing good feed and ensuring good snail farm management
Without artificial climate control, successful commercial snail farming is more or less restricted to areas with the following characteristics:
- Temperature: a steady year-round temperature of 25-30 °C, and a low fluctuation between day-time and night-time temperatures.
- Day-length: a fairly constant 12/12-hour photoperiod throughout the year.
- Air humidity: a year-round relative air humidity of 75-95%.
These conditions correspond to the tropical rainforest climate zones – and they work best when there is no pronounced dry season or strong fluctuations.
Certain religions, notably the Islamic and Jewish faiths, specifically prohibit eating snails or snail meat – a fact to be considered when planning a snail farming venture in regions where these religions are present or dominant.
Local customs or cultural preferences may prevent people from eating or even handling snails – again a factor to take into account before embarking on snail farming.