Rohan Dalvi covers some scatter tools you can use to control copies in Houdini.
In Side FX Houdini, copy-to-points and scatter are simple yet powerful tools. With Copy to points, it might not be readily apparent how to rotate or affect objects you have copied randomly.
Rohan Dalvi shows how to control copies using attributes in Houdini and some scattering tools you get with copying objects.
Also of note is this tutorial from Inside the Mind that shows how to add variants of models using Copy To Points in Side FX Houdini.
About Rohan Dalvi.
Rohan Dalvi is a veteran 3D Artist and Trainer covering Side FX Houdini techniques and concepts.