Hi
Your boys are exploring; guinea pigs, like other rodents don't have a vomiting reflex, so they explore their world by chewing and tasting, and learning what is safe to eat/digest and what is not.
Please be aware that with growing knowledge there has been a massive rethink over the last 2 decades and especially the last decade, including a better understanding of dietary needs and how the dental system works.
The crucial grinding molars and premolars at the back have evolved against the highly abrasive silica in grass fibre, which should make just over three quarters of the daily food intake; otherwise they can grow spurs trapping the tongue. In a functioning dental system the incisors are sharpening against each other. Any overgrowth at the front is generally an indication of overgrowing premolars and molars. Chewing toys are enrichment but they are not needed to keep the incisors short.
The other 20-25% of the diet replaces the supplementary role of wild forage, but that includes 1 cup per piggy per day of fresh veg, forage and herbs (ideally no or very little fruit, tomatoes and carrrots), pellets (which should only add up to max. 1 tablespoon per piggy per day but can be replaced by forage if wished) and - importantly - also any naughty treats.
Since pellets only have around 11% fibre and when in contact with saliva are too soft for grinding down the teeth, a diet too high in them and in fresh veg can lead to life shortening overweight, dental and digestive problems (higher risk of severe bloating).
We also recommend to not use bowls but to sprinkle veg and pellets around the cage, this not only minimises food bullying and issues with soiled bowls, it also counts as enrichment since it stimulates natural foraging behaviour.
You may find our diet guide helpful, which looks at diet as a whole but also at every food group in detail and gives an example of a balanced veg diet:
Long Term Balanced General And Special Needs Guinea Pig Diets
Since you cannot control the crucial hay intake by eye (guinea pigs do chew on cud), we strongly recommend a weekly weigh-in together with a body check in order to spot problems early.
These guides here explain the different roles of weigh-ins, BMI check and poo output play and what each access can do and cannot and how to judge whether a weight loss is alarming or not, depending on body and general BMI and they also help with learning what is normal or not with the body.
Weight and Weight Loss Explained: BMI, Weighing, Poos and Feeding Support Levels
Guinea pig body quirks - What is normal or not during the weekly check
Boar Care: Bits, Bums & Baths
We have got a very helpful information collection for New Owner into which 20 years of collective forum and half a century of private ownership experience have gone into, as well as literally well hundreds of thousands of questions. The guide format allows to update and add to our extensive forum resource, which contains all the practical how-to advice and in-depth information, which we cannot repeat in full in every post, seeing that we are all doing it for free in our own free time.
I hope that this is helping you to get up to a good start.
