1. Julius, _Pongo pygmaeus_:
Box stacking experiment
Box and pole experiment
Draw-in experiment
Lock and key test
2. Skirrl, _Pithecus irus_:
Box stacking experiment
Box and pole experiment
Draw-in experiment
Hammer and nail test
Other activities
3. Sobke, _Pithecus rhesus_:
Box stacking experiment
Draw-in experiment
Box and pole experiment
Other activities