Covering soil for houseplants

Covering soil for houseplants

I thought someone here might be able to help with a houseplant question. In the past I've used spanish moss (the grey stuff, at the suggestion of a friend) to cover the soil of my houseplants, both to help them retain moisture and to look a little nicer. (I get sick of looking at the dirt.) But the moss gets kind of gross after a while and I noticed that some of my plants had little black bugs in them, which seemed to go away when I took off the moss. (Not sure what these were, they were about the size of a period, with no distinguishable legs.) Last week I repotted several of my plants, and last night I decided to try using pea gravel (at the suggestion of another friend) to cover the soil. I really like the way this looks, but is there any reason why this wouldn't be good for my plants? I have about twenty houseplants now and I would like them to remain healthy! Thanks in advance for your help.
Hydrangeas – The Sea of Upturned Faces

Hydrangeas – The Sea of Upturned Faces

Hoping someone can name this plant

Hoping someone can name this plant

Crocuses!

Crocuses!

Pretties!

Pretties!

Bachelor Apartment

Bachelor Apartment

My terrace starting to *move*…

My terrace starting to *move*…