What's mounting my systemd automount?

I've set up a systemd automount for an sshfs in /etc/fstab approximately as follows:

me@server:  /mount/point  fuse.sshfs  noauto,_netdev,x-systemd.automount,x-systemd.idle-timeout=900,default_permissions,allow_other,uid=josh,gid=josh,transform_symlinks  0  0

This works great, except that sometimes I'll notice that it's mounted even though I've not accessed it recently. Looking in journalctl, apparently there's a process called pool that's causing systemd to mount it every so often:

$ journalctl -u mount-point.automount -n10Mar 04 22:17:39 hostname systemd[1]: mount-point.automount: Got automount request for /mount/point, triggered by 11546 (pool)Mar 04 22:53:03 hostname systemd[1]: mount-point.automount: Got automount request for /mount/point, triggered by 27856 (pool)Mar 05 00:31:36 hostname systemd[1]: mount-point.automount: Got automount request for /mount/point, triggered by 9083 (pool)Mar 05 01:44:21 hostname systemd[1]: mount-point.automount: Got automount request for /mount/point, triggered by 32232 (pool)Mar 05 17:32:31 hostname systemd[1]: mount-point.automount: Got automount request for /mount/point, triggered by 10771 (pool)Mar 05 17:59:01 hostname systemd[1]: mount-point.automount: Got automount request for /mount/point, triggered by 18662 (pool)Mar 05 20:05:10 hostname systemd[1]: mount-point.automount: Got automount request for /mount/point, triggered by 3259 (pool)Mar 05 20:36:21 hostname systemd[1]: mount-point.automount: Got automount request for /mount/point, triggered by 16858 (pool)Mar 05 22:29:33 hostname systemd[1]: mount-point.automount: Got automount request for /mount/point, triggered by 20812 (pool)Mar 05 23:39:16 hostname systemd[1]: mount-point.automount: Got automount request for /mount/point, triggered by 15976 (pool)

I've looked for binaries called pool on my system, but I can't find any, and there doesn't appear to be any process called pool running at the moment. I'd rather not hang around watching journalctl until something appears to try and find out what this is, though I guess I'll do that if I have to.

What's making systemd mount my automount?