Why Do Forests Sometimes Catch Fire on Their Own?

Sometimes forests catch fire on their own. Imagine you're a tree in the middle of a forest, it's hot and dry, and your leaves are starting to get really thirsty. Inside each leaf is something called resin, which acts like a kind of natural glue. When the weather gets super dry and hot, that resin can turn into smoke or even start burning by itself. It's like when you leave your campfire unattended, sometimes it catches fire without anyone around.