Carlos Pages knows how to take precautions before he opens a crate; the last thing the wildlife inspector wants is to find a deadly cobra loose -- again -- at Miami International airport.

He's one of a team of US Fish and Wildlife Service inspectors whose job is to root out anything irregular or illegal, both in the trade of live animals and animal products.

"We have cases when we've opened up the box before and there is a mamba loose in front of us. In that case, it's a hazard for all of us," Pages tells AFP, referring to the deadly snake of African origin.

This time could be dangerous, too.

So Pages and a few colleagues carefully, painstakingly open a large crate, using special tools that keep whatever may be in a box of live reptiles -- eight King Cobras and a number of frilled lizards -- at a safe distance.

"Whenever we do an inspection, we want to make sure there's nothing illegal that's mixed in with the venomous animals as well," explained Pages.

Trained as a reptile expert, he still spends his days with a team of workmates inspecting all manner of animal shipments -- from live fish to rhinoceros -- in a freight warehouse adjacent to the airport.

After getting a peek at the inside of the box with a tiny camera, the inspectors forge ahead with the business at hand: using a long tweezer type tool, they start opening the burlap bags, each containing one cobra.

Then they attach a glass cylinder to each one with tape so they can get a good look at their cold-blooded guests without risking a bite.

It may seem a strange shipment, but as far as the wildlife inspectors are concerned, everything is in order, and the animals are sent on their way. In Florida, it is legal to keep poisonous snakes, if you have a license.

- Massive illegal trade -

Not every inspection comes up clean and problem-free. Far from it.

In fact, in fully one in three shipments, inspectors identify irregularities, according to the USFWS spokesman for the US southeast Tom MacKenzie.

They run the gamut from inadequate documentation; to an extra animal in the shipment; to a surprise member of an endangered species; to parts of endangered animals (such as ivory handicrafts), which are seized.

It is incredibly tough work, largely because the scale of the mission is enormous.

Miami has a team of 10 inspectors, for a city that receives 13,000 shipments declared as wild animals each year and is a key crossroads for the animal trade in the Americas, according to MacKenzie.

Since Miami has many flights to Latin America, across the United States, and to Europe and beyond, many of the rare animals converge here by plane.

"One of the biggest challenges is doing as much as we can with what we have. And our tools are improving," Pages said. "But we are always trying to catch up with the illegal importers and exporters, they are always a little bit, a step ahead of us. And we are trying to catch up with them as much as we can."

MacKenzie stressed that the market in wildlife is massive -- way beyond people's imagination.

"The illegal wildlife trade is second only to drugs (in the US), it is a multibillion dollar business, that's the illegal aspect, and there is the legal aspect, that is also equally expensive," he said.

Adding to the pressure, his team is scrambling to avoid allowing illegal and potentially destructive species into the United States. These can potentially threaten native ecosystems, especially in Florida, which is suffering from a proliferation of invaders from Burmese pythons to lionfish and Argentine tegu lizards.

- Not cowhide boots -

The creative imagination of animal traffickers never ceases to amaze Sylvia Gaudio, another inspector on the team. She points to a table full of confiscated items: the shell of a Nicaraguan turtle, big cat skins, ivory handicrafts, a giant dried and preserved spider.

"This was a commercial shipment of leather boots, it was declared as regular cow leather," she said, indicating a load of odd-looking boots.

"One of our inspectors noticed there was something unusual about them, and when we took a closer look we realized they were crocodile boots" covered in ordinary leather to hide their provenance.

Some traffickers even have a special belt they use to stash tiny, illegally-traded birds, Gaudio said.

Many are brought in from Cuba and many die on the way. But those that do not fetch big money, she explained. That is, if the wildlife inspectors don't get them first.