Hi Tammy,
Glad I could help. I live in Fort Lauderdale and work in Boca, so I'm actually pretty close to you. Where did you get a roundtail? I'm looking to get a pair or two, but haven't been able to locate any. I was waiting until the Daytona show in August, but if I can find some before then...
There is a species of harvester that lives here in Florida, but HLs might not eat them. If you read through some of the earlier posts from just last week (those by Karu), you'll see that this is something under debate here. You should be able to find them fairly easily in WPB. The live in scrub areas, so if there are any natural pine/palmetto areas around, that's where you should be able to find them. Once you order some, you'll know what they look like (they look pretty similar).
Q1: Don't add more than about 10 ants at a time. If he/she doesn't eat them, they might attack him/her. I don't know about the little black ants, but the harvesters don't climb well, so you needn't worry about them climbing out unless there is wood or something that gives them a good grip. I keep my HLs in tanks without any cover, and never have ants climb out. Also, if you refrigerate them for about 30 minutes they become inactive, which makes them easier to handle. Be very careful with the harvesters, as they have a very nasty sting. Although alergies to them are rare, they are still one of the most painful insect stings, period. Much worse than bees or fire ants. I know from lots of experience as a kid.
Q2: Please do post a pic of your ants and your HL. I certainly can't promise that I can ID the ants, but I'll give it a shot. Unfortunately ants can be extremely difficult to ID, and there is no current guide to Florida ant species. But I'm hoping to maybe put one together myself over the next few years. Also info on where exactly they are living and a good idea of their exact size would help.
Q3: You mean you don't sing to him and rock him to sleep? No, I doubt he's lonely. Do you know if he's a he? HLs are solitary naturally, so they're just fine by themselves. Of course, if you decide to breed him, that'll be another story.
Q4: They don't need much water. I went to Walgreen's and got one of their generic spray bottles and set it for fine mist. I mist the lizards directly every couple of days, which is probably more than they need, but they have the option of drinking or not, and the excess will dry under their lights very quickly. I notice mine drinking maybe every third time I mist them. They don't usually lick the water, just sort of flex their throats and swallow what seeps in through the corners of their mouths.
So, do you make your own marinara sauce? Do you have a good recipe? I know, it doesn't have anything to do with HLs, but I also love to cook. 