Hedgehogs are easily recognized by their spines, which are hollow hairs made stiff with keratin. Their spines are not poisonous or barbed and, unlike the quills of a porcupine, cannot easily be removed from the hedgehog. However, spines normally come out when a hedgehog sheds baby spines and replaces them with adult spines. This is called "quilling". When under extreme stress or during sickness, a hedgehog can also lose spines.
A defense that all species of hedgehogs possess is the ability to roll into a tight ball, causing all of the spines to point outwards. However, its effectiveness depends on the number of spines, and since some of the desert hedgehogs evolved to carry less weight, they are much more likely to try to run away and sometimes even attack the intruder, trying to ram into the intruder with its spines, and rolling as a last resort. This results in a different number of predators for different species: while forest hedgehogs have relatively few, primarily birds (especially owls) and ferrets, smaller species like the long-eared hedgehog are preyed on by foxes, wolves and mongooses.
Hedgehogs are primarily nocturnal, although, depending on the species, they may be more or less active during the day. The hedgehog sleeps for a large portion of the daytime either under cover of bush, grass, rock or in a hole in the ground. Again, different species can have slightly different habits, but in general hedgehogs dig dens for shelter. All wild hedgehogs can hibernate, although not all do; hibernation depends on temperature, species, and abundance of food.
The hedgehog's back is made up of two large muscles, which control the positioning of its quills. There are about 5,000 to 6,500 quills on the average hedgehog, and these are durable on the outside, while being filled with air pockets on the inside. The hedgehog uses its quills to protect itself from predators, using muscles which draw their quilled skin to cover their full body, and pulling in the parts of their bodies not covered, such as their head, feet, and belly. This form of defense is the hedgehog's most successful, but is usually their last resort.
Hedgehogs are fairly vocal and communicate through a combination of grunts, snuffles and/or squeals, depending on species.
Hedgehogs occasionally perform a ritual called anointing. When the animal encounters a new scent, it will lick and bite the source, then form a scented froth in its mouth and paste it on its spines with its tongue. The specific purpose of this ritual is unknown, but some experts believe anointing camouflages the hedgehog with the new scent of the area and provides a possible poison or source of infection to predators poked by their spines. Anointing is sometimes also called anting because of a similar behavior in birds.
Similar to opossums, mice and moles, hedgehogs have some natural immunity against snake venom due to the protein erinacin in the animal's muscular system (although it is only available in small percentage and a viper bite, for example, may kill the hedgehog anyway).
Read more about this topic: Hedgehog
Other articles related to "description, physical, physical description":
... Sector Offset BPB Offset Length (bytes) Description 0x00B 0x00 2 Bytes per logical sector in powers of two the most common value is 512 ... the logical sector size is often identical to a disk's physical sector size, but can be larger or smaller in some scenarios ... sizes up to 32 KB and INT 13h implementations supporting physical sectors up to 1024 bytes/sector ...
... The main physical description of The Hidden is from Martín Viciana, a biographer admittedly unfavorable to The Hidden ... The Hidden was as a secret Jew in his account, as his description contrasts with the normal stereotype of a Sephardic Jew ... Nalle believes that this description was an intentionally unflattering one, in contrast with a prophesied savior that The Hidden had successfully presented himself ...
Famous quotes containing the words description and/or physical:
“The next Augustan age will dawn on the other side of the Atlantic. There will, perhaps, be a Thucydides at Boston, a Xenophon at New York, and, in time, a Virgil at Mexico, and a Newton at Peru. At last, some curious traveller from Lima will visit England and give a description of the ruins of St Pauls, like the editions of Balbec and Palmyra.”
—Horace Walpole (17171797)
“The term preschooler signals another change in our expectations of children. While toddler refers to physical development, preschooler refers to a social and intellectual activity: going to school. That shift in emphasis is tremendously important, for it is at this age that we think of children as social creatures who can begin to solve problems.”
—Lawrence Kutner (20th century)