perlite looks like Styrofoam .... but is volcanic in nature.... instead of squishy .. it would disintegrate if squeezed ...

but regardless .. perhaps it is time to start with some fresh medium for your pot .... this way you will know exactly what is in the pot.. and what is later introduced ....

i have no clue how insane your local squirrels are .... lol

ken

I'm pretty sure it's not perlite or vermiculite. It is spongy and springy, and there are bigger pieces that look like clusters of beads. I'm pretty sure it's styrofoam. Now I'm just really curious how it got there.

Some potting mixes use those styrofoam beads. By your description, the powers that be did a sloppy mixing job of the potting mix.

It wasn't there when I put the dirt in, and it wasn't there last time I planted in this pot (several months ago, possibly a year).

Then they could be snail eggs.

So here's a "technical" comparison to try.

-- If you squish snail eggs hard enough, they will eventually pop and ooze.
-- Did you add Osmocote or other coated fertilizer. If so, a sturdy squish will crumble/shatter the covering if the fertilizer has been used up.
-- If they truly are polystyrene beads, where the heck did the squirrels get them?

Squirrels will not stash styrofoam pellets although they will stash the similar looking "packing peanuts" made from corn. However, these corn based pellets generally disintegrate fairly quickly in the presence of moisture.

maybe the squirrel works for UPS at night?

ken

Even if there was no styrofoam in the soil mix you used, there may have been in the soil around any potted plants you added to the pot last year.

If you want to see a real mess, grow a nice thick carpet of Baby Tears, and watch a squirrel start burying acorns in it.

Sue