FLOYDS KNOBS, Ind. — Larry Gividen was busy one September afternoon trimming the weeds and tall grass around the bases of his apple trees when he encountered a potentially dangerous foe.

As he approached one heavily foliated tree he stooped under the branches to study them. Gividen raised his head into the lower branches of that tree. He bumped into a hornets’ nest he had not seen hanging there; he was likely blinded by the bill of the cap he was wearing.

The attack happened suddenly, and during the assault Gividen fell to the ground. He is not sure if he just collapsed or if the hornets knocked him down.

“They seemed to be mostly around my head and I started crawling to get away,” he said. “I was stung on the lip and on the ear. One got me on the nose and another, on the back of the neck.”

Gividen was momentarily blinded and in the mad scramble to crawl away he smacked the top of his head into the trunk of the tree. He remembered a sharp pain and the small welt it raised even through the ball cap. Smarting, but determined to get away, he kept crawling until the angry hornets left him alone.

He said there have always been hornets in his apple orchard. In fact, every year there are yellow jackets and two kinds of hornets that make their home around his orchard. He said they always come back because they eat the fruit.

Tim Gibb, an entomologist at Purdue University, said the most common hornets in Indiana are European hornets and the smaller bald-faced hornets. The bald-faced hornets are the most common and they sting humans most often. They have somewhat round or football-shaped paper nests that hang from the branches of trees.

On the other hand, European hornets often build nests in enclosed spaces, such as hollow trees, animal burrows and inside the walls of old or abandoned buildings.

These two types of hornets look very different. European hornets are bigger and look like oversized yellow jackets. Their bodies are striped in yellow and black. Bald-faced hornets are smaller and have white patches on the front of their head with white spots and stripes on their abdomen.

Gibb said the size of the hornet is not the main problem. “The danger is going to be created by the number of stings, and more particularly by a person’s susceptibility to the toxin,” he explained.

Gividen said he received 15 stings in all and they hurt quite a bit at first. But after the hornets left him alone, he was able to walk in the house where he sat down. After a short while he was back up and walking around the house.