How does an animal detect changes in its environment?

Answer 1

Sight
Sound
Scent
Temperature
Pressure
Amount of daylight
Some can sense the magnetic poles
Some can sense electricity
Observing other animals

Answer 2

Very interesting question.
Animals detect changes in the environment by vibrations, hearing, seeing, sense of smell, amount of sunlight and the Earth's magnetic forces (Moon and tides).
Ever noticed a dog sniffing the air or the ground? Have 14 dogs. The little Chihuahuas go crazy sniffing out creatures who passed through the yard the past evening-when we take them out to potty in the morning.
Owners are saved from house fires because cats/dogs smell the smoke.
Animals have a 6th sense too. Have a dog who can detect a certain negative behavior in men. Dog is 100% accurate.
Not trained to detect the trait. No one living in our home has the trait. We've had the dog since a pup.
Scientists think animals can detect minute vibrations that occur before a major Earthquake.
The majority of animals mate according to the amount of hours of sunlight in the day. Animals also start migrations for the same reason.
Sea animals like corals, spawn only during a full Moon during a specific month.

Answer 3

Animals use their brains.

Animal brains recieve input signals from sensors which respond to stimuli like light, heat and/or acoustic vibrations. They travel to the brain which then calculates a responce based either on instinct, experience or a combination of the two. Once the responce is calculated, the brain responds by stimulating the body's muscles to contract. Some responces are reflex actions. Animals run from danger without having to use their brains. The reflex is encoded in nerves outside their brain. In vertebrates, the spinal cord handles reflex actions.

Some animals can react to environmental changes even if they can not sence them directly. A circadian rythm is a behaviour pattern which expresses itself according to a set time schedule. Hibernating animals begin sleeping in the fall, even though their food supply will not completely exhaust itself until winter.

Answer 4

By its enstict, I guess.
But according to what I know, animals hear those ultrasounds that humans cannot and they get to know about changes immediately. They can also predict the weather in this way. For example, if a frog is not in the water all the time, it means that it is gonna rain. If it is mostly in the water,then it is gonna be sunshine.
Hope this is helpful.

Answer 5

Thousands and millions of years of evoloutionary progress. Animals also have extraordinary body clocks so are able to determine changing seasons etc.

Answer 6

instinct - like a cockroach running for his life from the attack of my foot trying to stomp on his head