# Hooks
> **_NOTE:_** In [Radix Babylon Network](../../../#radix-babylon-network),
> Hooks are currently only available for use by native packages.
Hooks define logic which get executed when certain system events occur.
There are currently three types of hooks:
| OnVirtualize | Called when a substate fault occurs on a virtual address of this blueprint type. |
| OnMove | Called when an object of this blueprint type is moved between call frames. |
| OnDrop | Called when an object of this blueprint type is dropped. |