Why does one of my tortoises always start to become so aggressive at this time of year? It's the same every time. After waking up from hibernation, there's never any problem for some timemale hermann's tortoise, but then he starts attacking the others. He becomes very aggressive and I've had to separate them in the past.

The way in which your tortoise is behaving suggests that he is a male. You can check this by looking at the underside of the shell. An curved central area to the shell is an indicator of a male, as is a relatively long tail (see photo).

The behaviour of your tortoise is very typical of the courtship of these reptiles. As the weather becomes warmer, he will start to pursue the females around the garden. This is most likely to occur in the morning, then he will rest for a period when the sun is at its hottest, before continuing on later in the afternoon. It's actually a sign that he is in good condition !

Tortoises do not have teeth, although the sides of their jaws can prove to be quite sharp. The way in which he snaps at their legs is unlikely to cause any injury however, even if he does grab one of them in his mouth. This is because their legs are well protected by scales, and also because the female will respond by drawing her hind leg under the cover of her shell as he snaps, making it difficult for him to gain any hold.

Similarly, if he advances round the front, she will draw the leg back against her body, so that again, the target area is reduced. The male is not trying to hurt her - he is simply trying to slow her down, so he can mate with her. It's interesting that smaller male tortoises are often more aggressive, presumably because they would otherwise have to chase quickly after a large female if she set off even at a moderate pace.