In Europe there are 3 kinds of tortoises: the Testudo Graeca, the Testudo Marginata and the Testudo Hermanni. The Testudo Hermanni is characterized by a carapace (superior part of the caress, the shell) strongly convex, oval, wider than the back part, generally long up to 25 cm., of yellow or brown color with black sketches. The ventral face of the caress takes the name of “plastron” and it is settled to the carapace. In the extremity of the tail there is a small horny case box (a kind of fingernail) and the plate upper-caudal is separated in two.

The head is short, thick, held up by a long and rather mobile neck, ready to reenter when there is a sign of danger. However if you put your finger under its chin, from down to up, easily the tortoise will lengthen its neck to let you scratch it under the throat.
Distinguishing its sex is not very easy, but pay attention to few characteristics. The tail is slightly longer in the male, while the females have a short and stumpy tail. The male has the back hollow of the plastron not very deep, the female’s hollow is bigger to allow the exit of the eggs. Besides, females at the same age are bigger. In the young tortoises up to 2, 3 years, a distinction is given by the opening of the plates situated on the plastron above the tail that are more opened in the males, in the females they form a more acute angle. But I think the easiest way to distinguish a male from a female is the position of the tail: if it keep a visible and straight tail, she is a female, on the contrary if it keep the tail folded towards a side and hides it, he is a male.
Every year, during the spring-summer, that is in the most active period of the life of a tortoise, each specimen “grows” in dimension both changing the skin, both increasing of one the circles of the plates. So you can calculate the age of the youngest tortoises counting the lines of growth of the horny plates on the carapace. Nevertheless, after some years, the horny plates can ruin and to be replaced, so there isn’t a precise method to calculate the age of the adult ones.
Tortoises have an excellent sight, they can distinguish shapes and colors and they can recognize people. They have a good orientation, and are sensitive to the vibrations even if the hearing is not very efficient. Instead the sense of smell is well developed and plays an important role in the recognition of food and sexes.
As all the reptiles, the tortoises are animal with cold blood, that is to say that the inside temperature of their body cannot be regulated , as it happens with the mammals, but it has to conform itself to that environmental. So, since the vital activity of the reptiles has to unwind within precise limits to survive, as soon as the sun is too hot they stop every movement to seek coolness of a shady place, while in the cold months they go into hibernation.
 
Two subspecies’ of the Testudo Hermanni exist: the Testudo Hermanni Hermanni (THH) and the Testudo Hermanni Boettgeri (THB). The first one is the western subspecies, the second is that oriental. It is enough simple to distinguish it: the THH has a coloration brighter and a more convex and pimply carapace; it can reach 20 cm. of length against the 25 of the THB; the plastron of the THH has got two continuous and well defined black spots, in the THB these spots are clearer and less defined. Besides, if we observe the relationship among the pectoral and femoral plates of the plastron, in the THH the pectoral suture is shorter than that femoral, in the HB the pectoral is longer than the femoral one.

Observing their head there are other thin distinctive characteristics: the THH has a head more lengthened and smooth in the contours that, in a general appearance, resembles to the head of a snake. The THB has a shortest and pimply head.

two kids born in the same day

you can notice the difference among the THH (on the left) and the THB (on the right)