0:00:02 > 0:00:03My name's Steve Backshall.
0:00:03 > 0:00:06Self-confessed shark-obsessed.
0:00:06 > 0:00:08This is Shark Bites.
0:00:10 > 0:00:13This time, we meet a master of teamwork.
0:00:14 > 0:00:16The blacktip shark.
0:00:16 > 0:00:21Easily identified by the black tips of their fins, these sleek sharks
0:00:21 > 0:00:25stalk the seas, sniffing out their supper before these toothy
0:00:25 > 0:00:27torpedoes launch their attack.
0:00:30 > 0:00:33Reaching lengths of up to 1.8 metres,
0:00:33 > 0:00:37they're not the biggest shark in their tropical territories.
0:00:37 > 0:00:38So, in order to survive,
0:00:38 > 0:00:42these clever creatures have a sensible solution...
0:00:43 > 0:00:44..power in numbers.
0:00:45 > 0:00:50But how does a shiver of sharks find and catch enough food?
0:00:50 > 0:00:54South Africa's Indian Ocean coast is a hot spot to find them.
0:00:57 > 0:00:59One thing that we always have on our side
0:00:59 > 0:01:02when we're trying to film sharks is their incredible sense of smell,
0:01:02 > 0:01:05particularly when they're sensing blood.
0:01:05 > 0:01:09So, we're dropping a drum full of fish guts into the sea
0:01:09 > 0:01:13and hoping that some sharks will sniff if out.
0:01:13 > 0:01:16And, just minutes later, we're in luck.
0:01:16 > 0:01:17Shark!
0:01:17 > 0:01:19One...two...
0:01:19 > 0:01:21Five, six!
0:01:21 > 0:01:24We are absolutely surrounded with sharks!
0:01:24 > 0:01:26Go!
0:01:28 > 0:01:30Oh-ho-ho!
0:01:30 > 0:01:32Amazing!
0:01:35 > 0:01:40Sharks can smell one drop of blood in a billion drops of water.
0:01:40 > 0:01:42And they've certainly homed in on our bait.
0:01:45 > 0:01:50Unlike us, sharks breathe and smell from different parts of their body.
0:01:50 > 0:01:53They breathe from their gills, which are here,
0:01:53 > 0:01:57and smell through their nares, or nostrils, which are here.
0:01:57 > 0:01:59Water's drawn in to the nasal chambers
0:01:59 > 0:02:03and over complex folds of skin which are covered in tiny sensory
0:02:03 > 0:02:06cells, which are very sensitive to smell.
0:02:06 > 0:02:10This helps the shark to detect where a smell's coming from.
0:02:10 > 0:02:12If a smell's coming from the left,
0:02:12 > 0:02:15it will hit the left nostril milliseconds before the right,
0:02:15 > 0:02:18and the shark will know to swim in that direction.
0:02:21 > 0:02:23And once they've sniffed out the source,
0:02:23 > 0:02:28blacktip sharks can be seen working like a team in intimidating groups.
0:02:31 > 0:02:33They corral their prey into a tight ball...
0:02:34 > 0:02:37..and, when the time is right, they strike...
0:02:39 > 0:02:42..from all angles, annihilating entire shoals.
0:02:46 > 0:02:48The blacktip sharks.
0:02:48 > 0:02:50Toothy torpedoes with
0:02:50 > 0:02:52a scintillating sense of smell,
0:02:52 > 0:02:57and perfect pack precision, make them the masters of teamwork.