Why is Karait more dangerous than the cobras?

Readers can find the answer to this question in the paragraphs following the narrator's information about basic mongoose history and fighting techniques.  Teddy is running toward Rikki-Tikki, and he comes across Karait.  The snake announces his presence, and he claims that he is very dangerous. 

"Be careful. I am Death!"

The narrator then goes on to state that the little brown snake has a bite that is as dangerous as a cobra's bite; however, the snake is much smaller.  The snake's small size is why Karait is so dangerous.  Because the snake is so small, Karait is much quicker than a cobra and can turn much tighter.  Rikki-Tikki doesn't know it, but he absolutely has to perfectly place his bite.  If he doesn't, Karait's turning speed will allow him to score a return bite on Rikki-Tikki.  

If Rikki-tikki had only known, he was doing a much more dangerous thing than fighting Nag, for Karait is so small, and can turn so quickly, that unless Rikki bit him close to the back of the head, he would get the return stroke in his eye or his lip.

Fortunately, Rikki-Tikki is quicker than Karait and manages to kill him.