Bugs appearing in anole lizard habitat?

i got an anole lizard about 3-4 months ago, i have bark bedding in his tank along with a few rocks and a little water plant. ive been feeing it meal worms and baby crickets, he's doing just fine but my question is.. maybe a month after i got him i started to notice little teenie tiny miniscule(almost a speck size) grey bugs all up in the bark bedding, on the rocks, pretty much everywhere.. but i have no idea what they are or where they came from.. i'd like to know what they are and if they are dangerous to the lizard. also about a month after i got him, there randomly appeared an all black beetle kinda shiny(looks like leather).. and a month after that another one exactly the same appeared out of nowhere. i'd also like to know what those are/where they came from and if they're safe for my lizard to be around.. he hasnt tried to eat them, they kinda just live in there harmoniously. Any and all answers will be greatly appreciated.