Growing sshd process count

[Mayuresh <mayuresh%acm.org@localhost>]

On NetBSD 9.2 amd64 VPS I noticed system slowness and top showed too many
ssh processes - 49 to be precise.

I have blacklistd enabled and approximately in every 2 to 3 minutes a new
IP address is getting blocked.

Using console access I stopped ssh service, killed sshd processes and
restarted. As of writing this the count of sshd processes is 10 again,
when only 2 ssh sessions are shown in `who'.

What explains the count of these processes and what precautions shall I be
taking?

-- 
Mayuresh