I want my Home Automation to check if my Amazon Alexa devices are present on the network or not. However, Amazon Alexa devices cannot be pinged.
NMAP comes to your help (If you do not have NMAP installed, apt install nmap should solve the issue).
The following code will give you a 1, if an Amazon Alexa device is present at the given IP address. It gives you a 0 if not.
nmap -T4 -F 192.168.178.120 | grep "host up)" | wc -l