Why would an ant go to sleep if you put it in the refrigerator?

Answer 1

While the activity level of the ant decreases dramatically, the ant doesn't actually go to sleep when placed in the refrigerator. It more accurate to say the ant becomes inactive or enters a state of hibernation as the temperature drops. While a short visit to the refrigerator is a great way to slow ants down, too long in the refrigerator or even a very short time in the freezer will kill the ants.

Ants are cold blooded, meaning they do not generate and regulate their own body heat like a mammal does. As a result, they have to control their environment in order to maintain optimal temperatures allowing them to work and live.

As an example, the Western Harvester ant covers the top of their colony mound with small rocks which collect and hold the warmth of the sun. They also clear all vegetation away from the immediate area of their colony, sometimes as much as two or three feet in diameter. This cleared space removes all shade and allows the sunlight to fall fully and directly on the colony throughout the day. This combination of behaviors allows the ants to collect and store as much solar heat as possible.

Too much heat is also deadly to ants. To cool themselves, ants tunnel deep into the ground where the temperature is more constant. During the daylight hours, the solar heat causes the temperature to rise in the top several inches of soil. In this situation, the tunnels near the top of the colony warm up. During the night time hours, the surface temperatures drop and the soil quickly looses its heat. This causes the tunnels near the top of the colony to cool throughout the night.

As the air temperature rises, you will find that all of the ants retreat into the colony tunnels to avoid the excessive heat of the midday sun. As the sun sinks lower in the afternoon sky you will see the ants emerge once again from their tunnels and return to actively scouting, gathering food, etc., which is made possible by the cooler afternoon and evening temperatures.

In the winter time, the upper tunnels of the colony can become too cold for the ants to live and work. If an ant is exposed to freezing temperatures it will quickly die. To maintain their colony, the ants plug of the entrances to their tunnels and retreat deep into the ground, below the frost line, where the temperature stays above the critical freezing point. In this way they are able to survive even the harshest winter temperatures.

With the arrival of spring, the ants clear the openings of their tunnels and once again emerge into the outside world where the temperatures are now more hospitable for their cold blooded bodies.

Answer 2

Ants are cold-blooded creatures, meaning their body temperature depends on their environment. Placing an ant in a refrigerator lowers its body temperature, which slows down its metabolism and activity, mimicking the conditions of nighttime when ants would naturally be less active and possibly sleep.