5 things to know for your New Day -- Monday, March 23

U.S. Sen. Ted Cruz of Texas announces his candidacy for the GOP presidential nomination

(CNN)Sen. Ted Cruz is running for President. Violence spreads in Yemen. And Singapore's founder dies.

It's Monday and here are the 5 things to know for your New Day

TED CRUZ

Let the politicking begin: U.S. Senator Ted Cruz of Texas has officially announced his candidacy for the Republican presidential nomination. "I'm running for President and I hope to earn your support!" he tweeted early this morning. Cruz, 44, is the first candidate to formally throw his hat in the ring for what's expected to be a crowded GOP primary -- one that's likely to include Jeb Bush and Scott Walker. Cruz has been a constant and vocal critic of the Obama administration.

    YEMEN UNREST

    Violence spreads: Yemen is a mess and a U.N. envoy says the Gulf nation is on "the edge of civil war." Houthi militants took over the airport in Taiz as they swept through the city and surrounding province over the weekend. Things have gotten so bad that the U.S. military has pulled its remaining personnel due to the deteriorating security situation. The U.S. had used a military base in Yemen to stage attacks against al Qaeda in the Arabian Peninsula. There are concerns terrorists will use the chaos to spread their reach.
    U.S. pulls military forces from Yemen
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    ISIS

    Brainwashed?: A Turkish lawmaker believes 11 foreign medical students have gone to Syria to work in ISIS-controlled hospitals. According to Mehmet Ali Ediboglu, the group includes seven Britons, an American, a Canadian and two Sudanese. After talking with their families, Ediboglu said he's convinced they've been brainwashed. But he did say that the students are in Syria to provide help, not to fight. Their parents want them to come home.
    Is U.S. medical student treating ISIS militants?
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    TROOP THREAT

    Possible ISIS connection: No one's heard of it before, but a group calling itself the Islamic State Hacking Organization has posted the names, photos and addresses of about 100 U.S. troops online. It calls for attacks against them. The file was posted online over the weekend before it was removed. Whoever posted it claimed to have hacked military data bases. U.S. officials take these things seriously Last month, Attorney General Eric Holder said that the threat of a lone-wolf attack inside the United States is one thing that keeps him awake at night.
    Hacking group threatens U.S. troops
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    LEE KUAN YEW

    Founding father: The man who put Singapore on the map, the nation's founder, is dead. Lee Kuan Yew died yesterday at age 91 after years of declining health. As the nation's prime minister from 1959 to 1990, he's credited with transforming the tiny chunk of land with few natural resources into a global economic powerhouse. His brand of capitalism -- which stresses the role of government rather than the free hand of the market -- has provided a blueprint for China's landmark economic reforms.
    Singapore's founding father Lee Kuan Yew dies
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    Singapore's founding father Lee Kuan Yew dies 03:35

    Those are your five biggies for the day. Here are a couple of others that are brewing and have the Internet buzzing.

    Spidey senses: Some guy in Michigan caught a spider in his garage on a night vision camera. We're not sure why he was recording to begin with.
    A quick science lesson: Prepare to be amazed. Also, take notes, there will be a test.
    Puppy preferences: Sing along with us: It's all about that belly, 'bout that belly, no neck.
    Childlike honesty: Listen closely when this little girl finds out she's going to be a big sister. Shhh, listen closely ...
    Mating Tortoises: Now that we have your attention -- this is why you don't interrupt mating tortoises, because they will chase you forever. It's not a fast chase, but they don't give up easily either.