Tuesday morning at the Agnes Irwin School, world-renowned scientist and activist Jane Goodall used her sense of humor - and a stuffed chimpanzee - to engage students on some serious issues.

More than 150 lower-school students listened closely as Goodall, 81, shared her celebrated experiences with chimpanzees. She also spoke of hope for the future and the importance of environmental activism.

She even drew quite a few laughs, especially when she directed the crowd to later search the Internet for "an octopus with coconut shells."

Wendy Hill, the Agnes Irwin head of school, who met Goodall at Lafayette College in 2013, invited her to Rosemont earlier this year.

"I think that her message of hope and leadership inspired a lot of girls here," Hill said.

Goodall, the founder of the Jane Goodall Institute, opened her half-hour presentation by acting out how chimpanzees say "Good morning."

Goodall, celebrating 55 years of working with Gombe chimpanzees in Tanzania, spoke to middle-school students later in the afternoon and was to lecture in the evening.

Goodall gives similar talks every year to educate people - especially the young - on the destructive effects she says modern societies have on Earth.

Goodall said her worldwide travels had taught her much about the environment.

"I've learned a lot more about the harm that we're doing as well as the amazing people who are putting things right and what some cities are doing to leave a less heavy environmental footprint," Goodall said.

She said one of her biggest challenges was convincing climate-change skeptics that the threat is real.

"The biggest thing is that we have to believe that change is possible," she said. "Because, if we don't, then what's the point of trying? We might as well give up.

"I don't want to think that way, and you don't want to think that way. We don't want our children to think that way."