Kinda neat

From their vantage point in a clearing at Mbeli Bai in the northern Republic of Congo, Breuer and his colleagues spotted a female gorilla, called Leah, studying a pond before venturing a few steps into it. She then turned back and grabbed a handy metre-long branch from the bank, which she proceeded to use as a 'walking stick', repeatedly prodding the pond's bottom with it. After apparently assessing the depth of the pond with each prod, she eventually moved almost 10 metres from the shore.

...

The researchers saw another female, Efi, using the trunk of a dead shrub as a bridge to cross swampy ground. Efi ripped the 1.3-metre-long, 5-centimetre-wide section from the ground and leant on it like a crutch while she trawled the marshy ground for food. Then she laid it down like a plank and strode over it.

— Gorillas branch out into tool use in Nature