It is important to remember that babies, from just a few days old until they get to about two years, will put anything and everything in their mouths and suck on it. It is instinctive and natural. Sucking is a reflex for breastfeeding from the mother. It is something all mammals share.
In the case of babies it is also a way of experiencing the new and unknown things around them and perceiving sensations such as the temperature, texture or hardness of an object, and it is also something they find enjoyable, gratifying and relaxing.
It is not an action to be concerned about, nor should the baby be discouraged from doing it as, little by little, as it grows and develops cognitively, it will continue evolving; for example, from sucking it will begin to bite, and gradually sucking will abandoned.
That said, we adults do have an obligation to prevent the risks that may arise when babies put something into their mouths.
The most important thing is to try to monitor the cleanliness and hygiene of the varied range of objects that babies put in their mouths in order to avoid infection. There is no need to be obsessive, in that the baby’s immune system will continue to develop and it is not a question of sterilizing every object they might touch or put in their mouths, but rather a case of observing regular habits of cleanliness.
Equally, or even more importantly, is keeping very small objects out of reach of babies as they could swallow them and cause choking or suffocating.
The risk of suffocation through swallowing an object does not go away when the baby grows, as small children also put things in their mouths, attracted by the shape or color which might lead them to think that the object is food or a piece of candy.
A great deal of care should also be taken with the toxicity of objects. On the one hand it is important to ensure that all the baby’s toys and objects are made with materials that do not release substances harmful to health such as polycyclic aromatic hydrocarbons. On the other hand, any toxic or damaging items such as cleaning products, glues, solvents, paint and even medication should be kept well out of the reach of children.
To avoid these risks, apart from being vigilant, it helps to keep the house and car clean and tidy: objects that might be dangerous should be collected and made inaccessible to children, ideally even out of sight, so they don’t crave them.