being reminded of that. but in reality some are very dangerous. around 4.5 million people are bitten by snakes alone around the world every year, and over half of those bites can lead to serious injuries or worse. and climate change, combined with accelerated urban development means that more and more people are coming into contact with things that can bite, with scientists predicting that the number of cases can rise even higher. to get an idea of what's out there here in mexico, i've come to a park near the capital to meet diego barrales, who's become a twitter sensation. he's the go—to guy when it comes to identifying potential danger. every day, hundreds of pictures are sent to him from worried travellers looking for reassurance after a close encounter or bite

from a spider, scorpion or snake. hi, diego. hi, eva. hey. how are you? i'm great. what deadly creature are we looking for here? 0h, we are looking for spiders and scorpions. they are quite common in this part of mexico. and it doesn't take long to find a scorpion. even though it's dark, they show up with a uv light, which is far more effective than using a traditional torch. and even though the scorpions you'll find here in mexico aren't as deadly as some that you might find across the middle east, they can still give you a very painful sting. wow! we put it in there. in he goes. diego, you've become quite a bit of a social media celebrity. how did that happen? it's because people want to know more about these animals. of course, people are afraid of this animal, so they're looking for help. these animals are, most of them,

seen as horrible creatures. but i think that through the work i have been doing in the twitter account and the instagram account, people are starting to see these creatures in a different way. despite diego's best efforts, more people are bitten here in mexico than anywhere else in the world. which is part of the reason why the country has developed one of the most advanced antivenom programmes anywhere. so i'm off to meet dr alagon, one of the world's leading authorities on antivenom, who has promised me a date with a potentially deadly rattlesnake. so, so scary looking! antivenom is made up from antibodies that can neutralize a potentially harmful or lethal sting or bite.

and the only way to create it is to start by collecting the venom in the first place. so he's about to milk the snake? yes, yeah, yeah. look. huge fangs! you see the the yellow venom. that's the venom? yeah, that's the venom. that snake does not look happy. dr alagon�*s team regularly extract venom from some of the world's most dangerous snakes and scorpions in a process called milking. the venom will then be used to create antibodies which will counter the poison, but more on that in a moment. so that's not very much, is it? well, actually, for us it's quite a bit, you know? and it's very concentrated and potent. ten years ago, dr alagon bought this ranch on the outskirts of mexico city, where he keeps

the animals that have the key to the success of the antivenom process. and they are these horses. what's the link between horses and antivenom? because as you can see, horses, they behave well. you know, they are large animals. so they can produce lots of blood. and then you can purify the antibodies that make the antivenom from the horse blood. the process is a slow but very controlled one. over a period of six months, a horse is injected with a small but increasing amount of snake, scorpion or spider venom that allows the horse to build venom neutralizing antibodies in its blood, which means they become immune to that particular venom. these antibodies are then extracted by dr alagon�*s cowboys—turned—scientists, which they then use to create life—saving serum.

the blood will be collected in a bag, and then it will be hung so that the cells, the blood cells, deposit in the bottom. and the plasma that contains the antibodies from which antivenoms are made remains on the top. how much antivenom do these horses actually produce? well, it will produce an average of 2,000 vials of antivenom, one donation, that's as far as scorpions. for snakes, you only get 200 vials. those are still pretty powerful numbers. yes. so what would you say to people who, you know, think that this might not be the right thing to do to horses, to these beautiful animals? well, i will say that these horses have been used for antivenom production for more than 130 years.

and as you can see, they are well treated, well fed. and i will say that that is more suffering — saving lives. and so far, there is not an alternative for that. if you think about it, each of these horses could potentially save thousands of lives. thousands of lives, literally. yes. if you do get bitten, the best advice is to not attempt to remove the venom yourself by sucking the site of the wound, but seek medical help immediately. don't drink caffeine or alcohol, both of which could speed up the rate at which your body absorbs the poison. and try to remember the colour and shape of the creature that's bitten you, as that will help medical staff to treat you quickly and effectively. so, since the use of antivenom has become more widespread in mexico, how have the numbers changed? yeah. mortality in the case of scorpions

has decreased by 86%, and in the case of a snake by 63%. that's a huge difference. huge difference. well, if you're thinking of coming here, don't let the idea of a few creepy crawlies put you off. there are loads of outdoor adventures to consider. here are just a few. history buffs will find exploring the remains of mexico's ancient civilizations irresistible. the mayan ruins of palenque are thought to be well over 1,000 years old, with hundreds of buildings spread over six square miles. or for those with a really adventurous side, how about cave diving in the yucatan peninsula? descend into one of the thousands of naturally formed, flooded sinkholes called cenotes. and there is a world to discover underwater. cenotes often begin with one large chamber which branches off into vast cave systems.

there is thought to be a cenote here for every skill level of diver. and how about mountain climbing in central mexico? at around 20,000 feet altitude, there are spectacular mountains here for expert climbers — but even novices can scale them with an experienced guide. treks to the volcano can also be combined with visits to the stunning pyramids of teotihuacan. while i was around mexico city, there was one place ijust had to check out. within the waterways of xochimilco lies a local legend. step onto an island here and you will find among a few small huts a place which some say is cursed. welcome to the island of dolls.

this strange little place has become a massive tourist attraction, but its origins are actually pretty dark. so, around 70 years ago, a young girl drowned nearby, and so the island's owner started placing dolls around here for her spirit to play with. but the story gets much weirder than that. after filling the entire island with dolls, the owner himself died in the exact same spot as the young girl. it is said he spent 50 years adding to the collection of dolls here before his own mysterious death in 2001. definitely not the kind of place i'd want to spend the night alone.

so it's probably for the best then that you can't actually sleep here, but you can visit the island as part of a day tour of xochimilco�*s waterways. it's not one for the faint hearted. i've never been to a place like this before. with good reason. it's absolutely terrifying. it's a great natural setting for a horror movie. hello. a cool and very changeable week on the way this week, but tonight, much quieter for many compared with recent nights, and with that, we could see quite a bit of frost around north and east of the country with some dense patches of fog. it will change to the

southwest later on — this approaching cloud, wind and rain responsible. under the clearing skies, the showers fade across scotland, good part of england, northeast wales. it's here we'll see a widespread frost. even some city centres will see temperatures drop below freezing, but it's in the countryside and the suburbs where we could be well below freezing to start monday morning. risk of ice, too, especially across some northern and eastern parts of scotland. but in the southwest, the temperatures rise into the morning. we've got this weather system — quite a complicated one — on the southern lows, where things could be quite blustery, and that could potentially be disruptive. devon and cornwall especially, we could see winds around northern coasts as they flip from southeast to northwest, touching around 70—80 mph. to go with that through the day, we're going to see some heavy rain, particularly in the morning — turning wet across much of wales after a bright start in the north, rain throughout much of the day in northern ireland with some strengthening winds. away from that, the midlands, east anglia, south—east morning sunshine gives way to cloud and rain for the afternoon in the far north of england, scotland, actually, even though the wind will be picking up,

making it feel particularly chilly in that breeze. many places will be dry with some sunshine, just a few showers in the far north and east. but it's across the north where we'll see even colder air move out of scandinavia as we go through into tuesday on the northern edge of our double—centred low, which�*ll continue to produce outbreaks of rain through the night and into the morning, especially for england and wales. breaking up, turning more showery, so about a chance of some afternoon sunshine at times. but whatever falls from the sky in that colder air in the far north of scotland, 0rkney and shetland will be a wintry mix of rain, hail, sleet or even snow, and it will feel colder than 6—7 celsius would suggest. now, another chilly start to the evening as we go through tuesday night, but into wednesday, the next band of atlantic weather fronts work their way in. an hour or two, if not more, of rain, but sweeping quickly northwards and eastwards across the country, turning to sunshine and showers later. the rain persisting into the afternoon across some parts of northeast scotland, where of course, the ground is saturated and it will be another fairly cool day as well. beyond that, temperatures will slowly lift up just a little bit, but just look at the weather symbols in our towns and cities — it is going to be a week where we'll

see yet more in the way of heavy rain at times. bye for now.

this is bbc news, broadcasting to viewers in the uk and around the world. i'm tim willcox. the headlines... delegates at the un climate conference in egypt agree a major deal on climate change, but critics say it lacks ambition. the qatar world cup kicks off with a lavish opening ceremony in doha. but in the opening game, the host nation loses 2—0 to ecuador. a shooting outside a gay nightclub in the us state of colorado leaves five people dead. a suspected gunman has been arrested. the suspect has been identified as anderson lee aldrich, a 22—year—old male.