Your little one is doing what we refer to as “connection seeking behaviours”. This is how children get their emotional cup filled.
This is a very normal healthy developmental stage. When they are babies they cry, smile or do little tricks like wave or clap hands to get adults to connect with them. In an attempt to connect with you he/she is exploring other ways to do this. Your response to connecting with this child would be quick when he/she pushes other babies, so in a sense the little one is getting “their cup filled”, although not in a very positive way!
Think about how often you connect with this little one, outside of doing routines eg: nappy change, feeding? Do you initiate time together? How long do you spend when you do? Set some time aside throughout the day to initiate play moments. If you are busy take time for a simple smile or wave across the room and say, “Oh I see you, you are very clever” or “ I am over here if you need me”. When the little one is playing independently say, “Oh that’s nice. I see you are playing with your toys/friends”. Reinforce positive behaviour moments.