With your eyesight preferably It looks like a ball as @The Grym Reaper said. If you see some in the enclosure, take it out with a tong. If you can´t see any, don´t fret about it. Sometimes they will remain in a burrow, under some substrate etc. I just remove those I can see laying around.
If the T leaves them out in the open then I tend to spot them quite easily, they do sometimes bury them or dump them in the water dish though.
No, why would you do that?!?! The tarantula needs time to settle and will always be stressed if you rehouse it every second month. One of OBTs has stayed in the same enclosure for more than two years now and I have no intention to change the substrate any time soon.Thanks i change the substrate every 2 months but nether take the bolus it just comes out every 2 months, is this ok.