A student displays forensic methods employed in criminal investigations during the National Biologists Night in Warsaw, capital of Poland, Jan. 11, 2019. The eighth edition of the National Biologists Night was held on Friday at lots of universities all around Poland attracting thousands of visitors. (Xinhua/Jaap Arriens)

Visitors try out laboratory experiments during the National Biologists Night in Warsaw, capital of Poland, Jan. 11, 2019. The eighth edition of the National Biologists Night was held on Friday at lots of universities all around Poland attracting thousands of visitors. (Xinhua/Jaap Arriens)

A skeleton of a dinosaur is seen during the National Biologists Night in Warsaw, capital of Poland, Jan. 11, 2019. The eighth edition of the National Biologists Night was held on Friday at lots of universities all around Poland attracting thousands of visitors. (Xinhua/Jaap Arriens)

Visitor look at bacteria through a microscope during the National Biologists Night in capital of Warsaw, Poland, Jan. 11, 2019. The eighth edition of the National Biologists Night was held on Friday at lots of universities all around Poland attracting thousands of visitors. (Xinhua/Jaap Arriens)

A biology student prepares an experiment during the National Biologists Night in Warsaw, capital of Poland, Jan. 11, 2019. The eighth edition of the National Biologists Night was held on Friday at lots of universities all around Poland attracting thousands of visitors. (Xinhua/Jaap Arriens)

Fluorescent microbes are seen during the National Biologists Night in Warsaw, capital of Poland, Jan. 11, 2019. The eighth edition of the National Biologists Night was held on Friday at lots of universities all around Poland attracting thousands of visitors. (Xinhua/Jaap Arriens)

Visitors are seen at a stand where the workings of human parasites are explained during the National Biologists Night in Warsaw, capital of Poland, Jan. 11, 2019. The eighth edition of the National Biologists Night was held on Friday at lots of universities all around Poland attracting thousands of visitors. (Xinhua/Jaap Arriens)

Visitors look at plant life magnified through an electric magnifier during the National Biologists Night in Warsaw, capital of Poland, Jan. 11, 2019. The eighth edition of the National Biologists Night was held on Friday at lots of universities all around Poland attracting thousands of visitors. (Xinhua/Jaap Arriens)