Soldiers from Lancashire are spending five weeks in the jungles of Central America.
They are learning how to survive and fight in a hot, humid and unforgiving environment.
Six hundred men of 2nd Battalion the Duke of Lancaster's Regiment (2 LANCS) are the main force among a larger, 800-strong battle group deployed on Exercise Tropical Storm in Belize.
The remaining 200 soldiers include men and women from attached units of artillery, engineers, logistics and medical.
Under the guidance of both British Army instructors and Belizean military experts, they will gain insight into the art of soldiering and staying alive in the jungle.
The jungle warfare specialists have taught classes ranging from finding food, sourcing water and making fires, to evacuating casualties after being ambushed by enemy forces.
The soldiers are also trying to avoid the dangerous wild inhabitants of the Yalbac jungle, such as coral snakes, scorpions, crocodiles, pumas and tarantulas, as well as the noisy howler monkeys keeping the soldiers awake at night with their loud and distinctive 'howls'.
The five-week jungle programme will culminate in a final week-long exercise, with Belize Army soldiers playing as enemy.
This will be the final stage in 2 LANCS achieving its goal of converting from an armoured (in vehicle) infantry battalion to a light role.
Lt Col Mark Kenyon, commanding officer for 2 LANCS, said: "We are re-roling from an armoured infantry battalion, which is the role we performed in Iraq last year, to a light role battalion spending far more time on our feet, carrying our weapons and equipment and operating in complex terrain, such as the jungle or the desert."
He said this was in preparation for deployment to Cyprus this summer and from there to operations, most likely in Afghanistan.
Lt Col Kenyon added: "Out here in the jungle, it is hot and humid with plenty of vegetation.
"We are learning to cope in these conditions and later how to soldier and fight in those conditions."
Kingsmen Owen Herbert, 22, from Scale Hall Farm, Lancaster, Ryan Chapelow, 20, from Ridge, Lancaster, Kevin Stapleton, 23, from Gregson Lane, near Preston, Paul Briggs, 27, from Clitheroe and Sapper Joanna Christopher, 23, from the Leyland area are taking part in the jungle training.
The soldiers will then return to the comparative luxury of the permanent UK training camp in Belize.