Hi
They might be some type of spider or insect egg but looks more like some type of mold.Unfortuneately ,warm terrariums are great places to grow all kinds of fungi lol You can physicly remove them but I'll bet they'll pop up again.
They don't seem to do any harm so i just let them come and go. If you have no animals you could use a fungicide
Gary

I get these all the time in my bags of soil that I keep sealed. They must be a fungus of some kind, even though they do look like eggs! They do seem to be harmless though, and removing them is an on-going thing, as they seem to return out of nowhere. Did you start with a fresh bag of sterilized soil? If they really bother you a lot you could try starting over with a different substrate, like vermiculite, but if you're okay with them, just leave them or remove them periodically. I've got them all over the surface of the soil on one or two of my houseplants.

It's not a kind of soil mealy bug is it?

Definitely not.

It's a fungus.

Sahoy, the reason removal made no difference is those are merely the fruiting [reproductive] bodies. The rest of the fungus is almost definitely spread throughout the media. On the positive side though, I've never seen any indication that this type harms anything.

Oh yeah, I knew that. . . duh! =) Mushrooms are so cool! And yeah, I've never seen this type do any damage either.

Do you have a small 10x hand lense such as botanists use? This sort of thing is useful and enjoyable. These hand lenses are small, like a coin, thick, and often on a string so you can wear it around your neck while hiking in the woods. (I wish I knew where mine is.)

If the white dots are smooth, shiny, well shaped--such as spherical or oval but consistant, then they are probably of biological origin. Eggs would probably not be distributed randomly over the soil. They might attach to glass or leaves as well. Mineral deposits also make white dots, dull, with no shape. Mushrooms can be a good thing overall since they break down organic matter into nutrients that plants can re-use. They are part of the cycle. The cycle can get out of balance though--in a closed environment like a terrarium. Open the terrarium and smell the air. If it smells fresh, you are probably OK. Mushrooms and bacteria can give a sweet musky smell if things are OK, or they can produce amonia, vinigar, alcohol, and toxic things. In that case your choice of soil is suspect. Too rich of soil can decay too rapidly, too much mold or bacteria grows, and you get problems.

I wouldn't go too much by the smell though. I think that my terrarium always smells kind of musty, like a forest floor. And since the natural forest smells like that, I'm not worried. =) When I had soil for a substrate, it smelled TERRIBLE when I was scooping it all out, so I'm really glad i switched to bark chips! I also don't get these little mold things with the bark. No mushrooms either though. . . =(

I got this mold/fungus too! It seems to have spread up the stems of one of my ferns, but the fern itself is growing happily. I shall give everything a prune, let it dry out a bit and ignore I guess.