(USA TODAY) -- When the day care center in Sartell, Minn., where Jessica Ward takes her two children installed a fingerprint ID entry system last year, she thought it was a great idea.

Playhouse Child Care Center already had a keypad that required parents to enter a four-digit code. But Ward said she liked the peace of mind that comes with knowing that anyone picking up a child from the center must first prove their identity.

"I'm all about more security when it comes to my kids," Ward said.

A growing number of child care centers nationwide are turning to biometric technology to ensure that only parents or authorized caregivers can enter and leave with a child. Biometric systems use distinctive human characteristics, such as a fingerprint or thumbprint, to identify someone before the door will unlock.

"There's no way of faking it or bypassing the system or anything like that," said Ted Pichler, owner of the Learning Curve Child Center and Preparatory Preschool in Gilbert, Ariz., one of the first in the nation to adopt biometrics when it opened in 2004.

The National Center for Missing and Exploited Children doesn't keep statistics on child abductions from day care centers, which are rare. However, child care centers often serve families involved in custody disputes, where one parent isn't allowed to pick up the children, Pichler said. A fingerprint system can help avoid problems because "there's no way for them to access the center," he said.

Playhouse Child Care Center in Sartell chose a fingerprint ID unit when it was upgrading its security system last year because it was easier for parents than remembering a code and more secure, co-director Molly Olmscheid said.

"I do like it because it is so individualized," Olmscheid said. "Parents can't just give so-and-so their security code."

Most child care centers still use an access system that requires a key code to get into a classroom, said Linda Kostantenaco, president of the National Child Care Association.

Procare Software, an Oregon-based company that sells security and access systems to child care centers, saw sales of biometric-enabled units increase from 790 units in 2009 to 2,210 last year, said Shawna DeVore, executive software consultant.

The systems also help day care providers track children and hours spent at the center for billing purposes and to prevent fraud. And they're a good tool for communicating with parents, who can view their child's schedule, balance owed and other information when they sign in, DeVore said.

Procare's biometric readers cost $85, and the software ranges from $330 to about $1,700 depending on the size of the center, DeVore said.

For most parents, making sure their child is in a secure environment is a top consideration when choosing child care, providers say.

"Ninety percent of the people that come into our building say the secure door is a great thing," Olmscheid said.

Among them is parent Melissa Steffes of Rice, Minn., who noted that fingerprint scans are becoming commonplace at fitness centers and even tanning salons. She said she likes that Playhouse, where her 14-month-old daughter attends, is using one. "That tells me that they're doing everything they can to be proactive and taking advantage of the technology," Steffes said.

A few parents initially express concern that being fingerprinted is an invasion of privacy, Pichler said.

DeVore said the systems actually take a picture of the fingerprint and turn it into a binary number. The information isn't stored or sent to the FBI, she said.

Heartfelt Impressions Learning Center in Lake Orion, Mich., switched to a biometric system as soon as the technology became available, said Rhonda Meyers, owner and program director.

"You always have to think about the parents and how can you make life as safe, but as less stressful and complicated as possible," Meyers said.

Biometric technology continues to evolve. The Learning Curve's first system used a thumbprint reader, Pichler said. About a year and a half ago, the center updated to a system that requires a parent signature and identifies the signer's handwriting.

"It doesn't read what you sign. Rather, it reads how you sign," Pichler said.

Day care providers say technology can only go so far in protecting kids. Although they caution parents never to hold the door open for someone they don't know, it does happen.

Having a consistent, well-trained staff is key to avoiding problems, Olmscheid said.

"It's our policy to always stop and question," she said. "The (staff) really are great at questioning people they don't know."

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