Let's say a malicious host connects to a network. It doesn't wish to identify itself to other devices on the network unless it wants to (eg: for a desired conversation). From what I understand, the standard way to scan for all devices on a network is through a program such as WNetWatcher which will issue an ARP request to every IP address on the network subnet, to which it receives an ARP response for every device.
Could the malicious host simply not respond to the ARP request, and thus remain hidden?