Some income investors have a special kind of fear of heights. I'm not talking about being afraid of standing on a ladder or peering over a cliff. This fear relates to stocks with sky-high dividend yields.

To be sure, there are often good reasons to be concerned when a stock has an exceptionally high yield. It could hint at underlying business problems and/or an unacceptable level of risk. That's not always the case, though. Investors don't always have to worry when stocks have really high dividend yields. Here are three ultra-high-yield dividend stocks you can buy right now.

1. Ares Capital

It would be a stretch to maintain that Ares Capital (ARCC 0.09%) has Warren Buffett's seal of approval. However, you'd be totally correct in saying that Ares is Buffett's highest-yielding dividend stock. Although Berkshire Hathaway doesn't directly own Ares Capital, it ranks among the holdings of Berkshire subsidiary New England Asset Management.

Ares Capital's dividend yield currently stands at nearly 9.9%. This high yield isn't the result of the stock being beaten down. Actually, Ares' shares are up a little year to date and outperformed the overall market in 2022.

Ares Capital's juicy yield is due to two primary factors. First, it's a business development company (BDC) registered as a regulated investment company. This means Ares must return at least 90% of its income to shareholders as dividends to avoid paying federal taxes. Second, Ares Capital continues to have plenty of income to return to shareholders.

BDCs provide financing to small and medium-sized businesses. That can be risky, especially during periods when default rates are high. Ares Capital, though, is less risky than most BDCs. Why? It focuses primarily on lending to upper-middle-market businesses. Its portfolio is also highly diversified.

2. Enbridge

The fortunes of some energy stocks hinge on oil and gas prices. However, that's not the case for midstream energy stocks such as Enbridge (ENB 0.51%). Nearly all of Enbridge's cash flow is either contracted or set by regulators.

Enbridge ranks as one of the biggest pipeline operators. The company transports around 30% of the oil produced in North America and 20% of the natural gas used in the U.S. It also delivers natural gas to 3.9 million customers in Canada.

Income investors will probably like Enbridge's dividend yield of nearly 6.9%. And they'll almost certainly love the company's dividend track record: Enbridge has increased its dividend for 28 consecutive years.

It should also be reassuring that Enbridge is building up its renewable energy business. The company acquired Tri Global Energy, the third-largest developer of onshore wind farms in the U.S., in September 2022. It's also investing in solar power and carbon capture.

3. Enterprise Products Partners

Many of Enbridge's positives also apply to Enterprise Products Partners (EPD -0.07%), another top midstream energy company. Enterprise Products Partners operates over 50,000 miles of pipelines, 29 natural gas processing plants, and other midstream assets.

Enterprise looks even more attractive than Enbridge on several key fronts. For one, the stock delivered greater gains in 2022 and so far in 2023. Despite this outperformance, Enterprise Products Partners' shares still trade at a much lower forward earnings multiple than Enbridge.

The company's dividend yield of 7.5% also beats Enbridge's yield. However, Enterprise lags just a little in growing its distribution, with 24 consecutive years of increases.

Enterprise Products Partners isn't as focused on renewable energy as Enbridge. But the company predicts that the demand for oil, natural gas, liquid natural gas, and petrochemicals will grow for years to come.